Knurling is a process of impressing a pattern of lines or diamonds or other repeating shapes around the circumference of a circular object. There are many methods and tips here useful to home hobbyists, whether they have a large or small metal lathe. If you got to this file directly from my HOME PAGE, return there by using your browser's back button. BUT if you came to this file as the result of a web search engine, see more than 70 additional files on my home page Machining and Metalworking at Home http://www.janellestudio.com/metal/ SAFETY WARNING BEWARE: DO NOT ASSUME that any subject matter or procedure or process is safe or correct or appropriate just because it was mentioned in a news/user group or was included in these files or on this site or on any other web site or was published in a magazine or book or video. Working with metals and machinery and chemicals and electrical equipment is inherently dangerous. Wear safety devices and clothing as appropriate. Remove watches, rings, and jewellery -- and secure or remove loose clothing -- before operating any machine. Read, understand and follow the latest operating procedures and safety instructions provided by the manufacturer of your machine or tool or product. If you do not have those most recent official instructions, acquire a copy through the manufacturer before operating or using their product. Where the company no longer exists, use the appropriate news or user group to locate an official copy. Be careful -- original instructions may not meet current safety standards. Updated safety information and operating instructions may also be available through a local club, a local professional in the trade, a local business, or an appropriate government agency. In every case, use your common sense before beginning or taking the next step; and do not proceed if you have any questions or doubts about any procedure, or the safety of any procedure. Follow all laws and codes, and employ certified or licenced professionals as required by those laws or codes. Hazardous tasks beyond your competence or expertise should also be contracted to professionals. Let's be really careful out there. (c) Copyright 2003 - 2008 Machining and Metalworking at Home The form of the collected work in this text file (including editing, additions, and notes) is copyrighted and this file is not to be reproduced by any means, including electronic, without written permission except for strictly personal use. =========================================================================== Posted by Ted on November 19, 00 at 07:06:24: In Reply to: antique knurling Q posted by Stephen Thomas on November 18, 00 at 15:49:59: I have a number of antique (1860's) woodworking handtools with the usual complement of coin edged screws and nuts for hand adjustment. What is curious to me is that these all have radiused (round) edges, and the spiral (helical?) coining follows the radius. Would this have been done with something resembling a radius generating turning tool equipped with a straight or helical knurl? Or would there have been specially made concave knurls made to form the convex shoulders? The pieces tend to be 1/2" to 3/4" diameter, maybe 1/8"- 3/16" or so thick. This is largely idle curiosity. I mean, what were they thinking in 1867 or so? But I do need a replacement on one tool and don't want to reinvent the (circularly knurled) wheel for one item. TIA smt Chris Heapy has instructions for making concave knurls on his web page at: http://www.btinternet.com/~chrisheapy/knurling.htm ------- Posted by Stephen Thomas on November 19, 00 at 10:39:56: In Reply to: Re: antique knurling Q posted by Ted on November 19, 00 at 07:06:24: Ted- thanks, I'm glad to get this info. The knurls he describes would be quick to make, especially if the end mill he uses was rounded on the corner to give the same profile both ways. (rather than a saw tooth profile from the straight 1/4" end mill he describes). The knurled patterns I'm looking at have helix angles of 40* from the faces of the nuts (50* from the axis). I may take a shot at making these with a tiny formed cutter held at the helix angle and just cut in and out like Chris describes with his. Some I'm looking at look like the knurls may have been generated, like cutting a helical gear. Must have been something in 1866 - 67 with the carbon tools and dividing equipment available then. When was the first commercially available pocket watch made? Thanks smt ------- Posted by Conrad Hoffman on November 18, 00 at 22:00:38: In Reply to: antique knurling Q posted by Stephen Thomas on November 18, 00 at 15:49:59: I have a couple concave and convex knurls that I picked up in a used tool shop. They give a fine pattern similar to that on the brass adjusting knob of a Stanley Bailey plane. I use them now and then for scientific instrument parts and knobs where a conventional knurl just isn't right for the job. I'm sure one or more of the knurl suppliers will list something similar. ------- Posted by doug on November 18, 00 at 19:52:50: In Reply to: antique knurling Q posted by Stephen Thomas on November 18, 00 at 15:49:59: I've run across a couple of makers of knurl wheels that can supply the type you're asking about. I can't recall any names just now, though. Generally, those type of knurling processes use a single wheel with a blank closely sized so the knurl repeats it's pattern exactly as the wheel feeds in. ------- From: Rich Dean Date: Fri Jan 7, 2000 6:07pm Subject: Re: knurling steve tarvin wrote: > does anyone know the formula for figuring the proper knurler pitch > I have a full size lathe and im tired of bad looking knurles I thought > I saw the formula once in HSM but I cant seem to find it. Any help > would be appreciated. steve Steve, there have many arguments on this in mags and on r.c.m for years. My experience has been, forget the fancy engineering. It really doesn't help. The trick seems to to be to adjust in some bite and run the wheels onto the work from the edge watching closely to see if they track, if not, put on a little more bite and try again. Be sure to use very low speed, same as cutting off) and lots of oil. Also brush away chips as fast as they form. The first bite must upset the metal enough to allow tracking. I only use and highly recommend the balanced (scissors) type knurler. Roll the lathe saddle slowly left and right as needed until the knurl is just fully formed. The least number of revolutions as possible. Good luck, Rich D. ------- Date: Thu, 22 Mar 2001 01:34:15 -0800 From: S1 Subject: Re: Knurling tools for 6" Craftsman lathe Actually, you can make one that will use a standard knurling tool. You have to machine your own. Roughly here's what you do. 1) buy or cut a cube of mild steel about 1.5-2" wide/thick/long 2) Drill a hole and into the center of the stock, and lock the cube of stockinto your tool post holder. Find a T-bolt that will slide into your lathe's tool rest, or mill one of you have access to a milling machine. 3) Buy an 1/2" End mill and put that into your lathe chuck. 4) using your crossslide as an X-Y axis, mill a slot into the stock that is 1/2" wide by 1/2" deep. 5) Drill and tap two holes above the slot for set screws. After doing this, you will have a block which will hold a standard knurling tool with a 1/2" square shank. Then just tighten the set screws on top locking in the knurling tool and you will be ready to knurl. Also, you will have an excellent holder for a small boring bars that they market for "mini-lathes". Gabe ------- Date: Tue, 22 May 2001 07:58:56 -0600 From: "John Shadle" Subject: I want a knurl, just like the knurl.... I've used the spark wheel from a discarded BIC lighter as a wheel for a small knurl. They're hardened and they're free. If you don't smoke, you can find them along the road when you're out for your bike or walk. John B. Shadle, CMC Online Clockbuilding: http://geocities.com/jshadle.geo/online_clock_building http://geocities.com/jshadle.geo/ ------- Date: Tue, 22 May 2001 18:27:35 -0700 From: "Nicholas Carter and Felice Luftschein" Subject: Re: Re: Knurling A better URL for this (there are 3 drawings) http://www.cartertools.com/index.html#AAT http://www.cartertools.com/nfhome.html > Nick Carter has plans for a knurling tool aht could be made larger to > a 2 inch capacity. His URL is http://www.cartertools.com/knurl01.jpg ------- Date: Wed, 23 May 2001 12:32:45 -0000 From: "Jim Lewis" Subject: Re: Knurling > Buy a larger tubing cutter and replace the wheels with knurls. Well I tried that last night and it worked nicely! The workpiece tests to drift off of the knurl after few turns but I plan to fix that with some washers that are larger than the knurl. BTW I did not want to take Nick's approach because I assumed that the small lathe could not handle the torque at 1.5" diam (alum). Jim http://www.emachineshop.com ------- Date: Sat, 13 Oct 2001 22:11:53 -0400 From: Tom Bank Subject: Re: changing knurls Kevin, I think that somehow you got an extra generous washer by mistake. Don't know how the guys at the factory got it together in the first place. I have a number of washers of that size but of different thicknesses. Now I know what to save the thin ones for ;-). Making yourself a new washer of the proper (thinner) thickness is probably the quickest and easiest way to rectify the situation,... probably quicker than running down to the hardware store. As for the alignment of the two knurls, don't worry, even if you were slightly out of alignment it would have no effect on the pattern that results. However, I can tell you from recent experience what will have a really nasty effect on the pattern. Following the directions on the instruction sheet, I have always been very generous with the cutting oil when knurling projects. Doing the actual cutting seemed to be hard work for the little lathe, but it always did a good job. That is, it did until I had three 7/8" diameter X 1" brass knurls to do for the same project, one right after the other. Then the lathe slowed down and suddenly -- with a nasty noise -- began stripping the knurls back off the third brass piece. I stopped the lathe as fast as I could and, when I pulled things apart, found that I had raised a burr on the shaft of the one knurl. It took no great amount of effort to realize that while I had been generous with the cutting oil, I hadn't bothered to oil the point where the knurl rides on the shaft at all! I whipped out a piece of 3/16" drill rod, cut a new shaft piece, and redid the knurls on all three pieces, this time oiling the the bearing point. My what a difference! I felt really dumb, but I guess that's what we call "a learning experience." At least the burr I raised wasn't large enough to damage the aluminum knurl frame when I forced the damaged shaft out. The one additional improvement I think I will make, after discovering how easy it is to replace that part, will be to make a new pair of shafts about 0.6" long and with a slight taper and ball on one end to make it easier to get the washers and knurls mounted. Last point: If you collect a range of knurls, purchase a third piece for each set of diamond pattern knurls you have. That way if you use two knurls with teeth cut in opposite directions you get a diamond pattern but if you use the two with teeth running the same way you get a spiral knurl. MSC sells the knurls individually. Regards, Tom Bank ------- kjw1x~xxjlink.net wrote: Subject: changing knurls Has anyone had problems changing the knurls on Sherline's knurling tool holder? I removed the old knurl, but am having difficulty inserting the new knurl, or for that matter replacing the old knurl. The slot the knurl fits in does not seem to be as wide as the two washers and the knurl. By my measurement the slot is about 0.245" wide. The knurl is 0.185" thick, one washer is 0.047" thick and the other washer is 0.028" thick. These add up to 0.260" or about 0.015" thicker than slot. Since the old knurl came out of the slot, I assume that the metal surrounding the slot had enough "spring" ("give"?) to accommodate the washers and knurl. But how do I stretch it back to force the stuff back in? Is there a reason for the two different thickness of the washers? Sherline's manual indicate that the washers are standard fittings that can be purchased at hardware stores. I tried buying washers, but did not find ones quite thin enough to fit. I can mill a pair of washers down to fit, but am uncertain as to how critical the alignment is for the two knurls to mesh. How critical is the tight fit of the knurls? Any help or advice would be greatly appreciated. Kevin ------- Date: Sun, 14 Oct 2001 18:29:30 -0000 From: kjw1x~xxjlink.net Subject: Re: changing knurls Tom: Thanks for the help. I milled the washers a little thinner. Everything still fits snug, but now can be taken in and out without a struggle. And, it still produces pretty knurls. The knurl in the other half fit fine without adjustment (Why didn't I check that first? :). I have only had my lathe a couple of months and am still learning this game. It helps to have someone confirm your hunches. I will heed your warning about lubricating the knurl shaft. I also liked you suggestion about purchasing extra knurls, nifty idea. Thanks again -- Kevin ------- Date: Fri, 02 Nov 2001 17:33:32 -0500 From: Tom Bank Subject: Knurling problems A while back I replied to someone who had a knurling problem, a thick washer or something like that. I stated in my reply that I had run into problems because I failed to oil the shafts the knurls ride on and the things bound up. I have to add to that. Just oiling the shafts is not enough. When knurling a number of pieces, especially with the smaller size knurls, it is necessary that one stop periodically, disassemble the knurling fixtures and clean them out. Fine *brass* dust especially combines with any oil to form a thick paste that will lock the knurl wheels up and strip the little ridges off your work piece. Does anyone in the group have experience with this? Should knurling of brass be done totally dry to avoid locking the wheels like this? I did come up with a device that helped me out in another respect. The knurled brass pieces I have been working on come out with the fine brass paste in the grooves. I cleaned them up with a very old suede brush -- after cleaning the old blue gunk off the brass brush bristles. Regards, Tom Bank ------- Date: Fri, 02 Nov 2001 19:31:35 -0500 From: "Rich D." Subject: Re: Knurling problems Tom: On the knurls binding up, I suspect the shafts they turn on is not up to the task. Shafts should be very hard/polished surface pins such as dowel pins. These will last a life time of ME use, when oiled, of course. Knurling is a difficult operation for anybody, even with good gear. The best success comes with a hard (forceful) application of the knurls on initial contact from the edge of the part and then the slide is moved more onto the part at this setting after it has been asertained that the coining is tracking properly. If not roll back off the part, apply more feed (for a harder cut) and try again. Once you get a good track, roll across the surface as needed. Now, one more detail. The knurling should be done at LOW RPM and in as few a number of revolutions as possible. This helps to prevent the formation of metal flakes that get rerolled into the surface. Brushing with a suede (brass) brush helps keep the cut clean but, if knurling is done quickly, there is no time for brushing. It's all over with in a few seconds. The scissors (balanced) style of knurling tool is by far the best for light machines and small parts. Once you are done, a light cut at each edge of the knurl track to clean up will get you a spiffy (I'm showing my age) looking job. RichD ------- Date: Sat, 03 Nov 2001 21:48:46 -0000 From: stevetarvinx~xxhotmail.com Subject: knurling FYI there is a shareware program at www.geocities.com/mklotz.geo/index.html#intro it is called knurl.exe This program will help you get perfect knurls. make sure you get an exact reading on the od. of your knurls as couple of thousanths makes a difference. ------- Date: Wed, 06 Feb 2002 00:23:17 -0000 From: "rlg1937" Subject: Knurling Could some tell me if there are any tricks to running a knurling tool. Thanks BOB G. ------- Date: Tue, 5 Feb 2002 19:46:44 EST From: JBZ564x~xxaol.com Subject: Re: Knurling run it real slow, , a real slow feed too.lots of oil. Use a a live center and run the carriage to the live center not to the chuck. make sure it's centered on the part and 90 degrees. Slow but works great ------- Date: Tue, 05 Feb 2002 19:58:25 -0600 From: "Skip Evans" Subject: Re: Knurling If you have one of the knurling tools that mounts into a lantern type holder, I would not use it. Build one as described in Home Shop Machinist. You can get a look at it at my website. http://www.skipevans.homestead.com/ProjectsPage.html I built mine because I felt that the original knurling tool placed too much pressure on the spindle and cross slide. ------- Date: Tue, 8 Oct 2002 00:25:20 -0700 From: "Dave Hylands" Subject: RE: knobs [REID SAID THE SHERLINE KNURLING TOOL WAS TOO SMALL] Hi Reid, I suspect that you'll have to make one then. There are fundamentally two types of knurlers (that I'm aware of) that you might consider for use on a sherline lathe. The traditional knurler has two wheels, one on top of the other and press from the side. This exerts a tremendous amount of side pressure on the bearings etc in the headstock and isn't recommended for the Sherline. A picture of one of these might look like: http://www.accu-trak.com/pictures/or2bh.jpg The other type is referred to as a scissors or clamp type knurling holder, and it places a knurl on either side of the workpiece. This means that very little pressure is actually placed on the headstock. An example of the clamp type would be: http://easyweb.easynet.co.uk/~chrish/r-t-7.jpg. Since you're looking at a 3" diameter piece, it won't fit over the crossslide, unless you use riser blocks. If you were to use riser blocks, then you could probably make a knurling holder similar in design to the Sherline one. Even if you were to purchase a knurling tool holder on eBay, you would almost certainly need to create custom holder. Dave Hylands Vancouver, BC, Canada http://www.davehylands.com/ ------- Date: Tue, 08 Oct 2002 01:23:14 -0700 From: "Scott A. Stephens" Subject: RE: knobs Check out http://www.cartertools.com/. On the main page their is a link to a build it your self knurlers that works with the Taig lathe so it should be adaptable to the Sherline. ------- Date: Wed, 08 Jan 2003 03:23:30 -0000 From: "Paul Fitch " Subject: Knurling success! I am new to the group and really enjoy it so far. I just wanted to share with you all my first impression with the knurling too from Sherline for the lathe. I attached it to the table and chucked up a piece of 1/2" aluminum round. Less than a minute later, I had a great diamond finish on this aluminum round. Great tool! Paul Fitch ------- Date: Wed, 8 Jan 2003 05:34:26 -0000 From: "Nelson Wittstock" Subject: Re: Knurling success! I share your feelings, Paul. I've learned a lot from this group. Also, last week I received a knurling tool and used it for the first time. I used round steel stock to make replacements for wing nuts by knurling it and threading a central hole. This is a great hobby. Nelson Wittstock ------- Date: Fri, 17 Jan 2003 05:49:03 -0000 From: "Paul Fitch " Subject: Help Knurling [SHERLINE GROUP] I just got my knurling attachment a couple of weeks ago and have had great success using it on aluminum. I tried to knurl brass tonight and found how difficult it can be to meet your marks (so to speak) with brass. With aluminum, the knurls seem to find their mark rather easy, but with brass it seems to be hit and miss (95% miss.) I know that diameter has a lot to do with it, but I don't even get repeatable results with the same diameter. Can any one give me some tips on knurling brass? Paul Fitch ------- Date: Thu, 16 Jan 2003 22:49:49 -0800 From: "Dave Hylands" Subject: RE: Help Knurling Hi Paul, so far, I've only knurled once, and it was brass. You can see some pictures here: http://www.davehylands.com/Machinist/Projects/Inkle-Loom-Screws/index.html I think I got lucky, because I never even tried for any particular diameter and they came out great. If I understand how this works, then following should hold (if I'm wrong, I'm sure that someone will point out my mistake). I checked the knurls that came with my knurling attachment and they have 34 teeth on them (which doesn't match any of the knurls listed by Sherline but oh well) and are 1/2" in diam. as close as I can measure, the "inner" diamater (measured valley to valley) is about 0.470". If we pick the midpoint, that would be 0.485. So, 0.485/34 = 0.014265 which means that your diameter should be some integral multiple of 0.014265 for "perfect" knurls. Note that the diameter of your material will increase slightly (because knurling is an embossing operation and displaces material, and doesn't 'cut' it). Dave Hylands Vancouver, BC, Canada http://www.DaveHylands.com/ ------- Date: Fri, 17 Jan 2003 13:39:10 -0500 From: RichD Subject: Re: Help Knurling Guys, All this fussing about knurling calcs, etc, is not neccessary. Any diameter will work with any knurler. This method works 90 percent of the time first try and is just a matter of trying again to get it correct. Turning off the old is not needed. Align the knurls on opposite sides of the work diameter (automatic on the Sherline device). -Close the knurls to touch the work. -Roll the carriage (lathe saddle) off the end of the work. -Advance the knurls (close together) a small amount to get a good bite. -Set the lathe speed to lowest RPM (~50). -Roll the carriage back onto the work a small distance. Stop to check the result. -If all is tracking well, continue moving the carriage across the work. -If not, advance the knurls slightly and try again. -If now tracking ok, but too much of a bite, back off the knurls a little. -Do not try to knurl the full depth in one pass, but 3 should do it. -For the cleanest result, form the knurls in as few passes and revolutions as possible being careful to stop just as the full depth is reached (diamond peaks are sharp). -The final pass is always ended by rolling off the end of the work. -This can all be done faster than the time it takes to read this. -The knurl wheels should have chamfered (beveled) edges. Square corners come on cheap knurls. -Excessive amounts of metal dust on the knurls must be removed with a brush while rotating. -Lubricate the knurls and work, if steel. Keep the knurl axles lubed as well. -Always allow extra material on the work to start the knurling and trim off later. I turn a small shoulder to accent the knurled area at each end. Happy knurling, RichD ------- Date: Sat, 18 Jan 2003 15:54:12 EST From: wanlikerx~xxaol.com Subject: Help Knurling Round/coin I have just finished getting a old Master clock working, and now want to build a Pendulumn Bob for it. My problem is that I want to knurl about a 1/8 wide rib on the top and the bottom of it. The knurl I want to put on it, would be round shape, about 180 degrees, and of a coin type knurl, completely around the ends of the bob. Where can I get a knurl, and more information on this form of knurling? Can I make the knurl to cut it? The finished knurl will not be flat in its final form, but a 180 arc. Thanks, bill ------- Date: Sat, 18 Jan 2003 17:00:23 -0500 From: RichD Subject: Re: Help Knurling Round/coin Bill: If you mean a concave knurl to make convex knurled parts, this type knurl is VERY hard to find, but you can make your own. A piece of drill rod (tool steel) is prepared and a tap is used for a hob (cutter). This is a little tricky to set up, but the idea is to rotate the hob against the work that is allowed to rotate freely. The hob (tap) determines the pitch and diameter (width) of the finished knurl. Making the knurl to a standard size will allow use in existing holders. Due to the force involved on the tap, a tip (center) support may be needed. Harden and temper as usual. RichD ------- Date: Sun, 19 Jan 2003 11:32:31 -0500 From: RichD Subject: Re: Knurls > > If you mean a concave knurl to make convex knurled parts, this type knurl is VERY hard to find, but you can make your own. This is what I have in mind, is there any site or URL that would show the technique you are talking about on using a tap to make the knurl. would the technique you are describing end up with the lines cut by the knurl parralel to the shaft of the owrk or knurl?????> Confused yet, bill CCED << Hi Bill, I don't know of any web site. The technique is very similar to gear hobbing. The helix in the hob just naturally pulls the work around as it cuts. Also, I've never seen any straight convex knurled knobs. I have many telegraph and telephone instruments which commonly use the angled and convex knurled form. Until a friend showed me his collection of concave knurls (the tools), I had no idea how to make them. He builds antique tool reproductions. But a straight knurl? All I can think of is a single V cutter shape on an arbor and the tool steel held in an indexer while the tool gashes the blank. A groove would be turned beforehand. RichD ------- Date: Sun, 19 Jan 2003 12:17:20 -0800 From: "Dave Hylands" Subject: RE: Knurls Here's some web pages on making worm wheels using a tap: http://www.tjanstrom.com/hobbingawormwheel.html http://pw1.netcom.com/~madyn/Metalworking/Gearmaking/Gear%20Making.htm To make a knurling tool, you'd need to use smaller diameter, hardenable steel, and a deeper cut into the edge, and of course hardening the wheel when you're done. Dave Hylands Vancouver, BC, Canada http://www.DaveHylands.com/ ------- Date: Sun, 19 Jan 2003 16:24:28 -0500 From: RichD Subject: Re: Knurls Dave and Bill, Yep, that's the ticket, exactly! RichD ------- Date: Sun, 23 Mar 2003 18:35:28 -0000 From: "flyrodbusdriver" Subject: knurling attachment I am new to the group and own a taig micro lathe and want to knurl nickle silver tubing to make reel seat hardware for bamboo flyrods. A small diamond knurl would be my choice of knurling. Any idea about where to get or how to make and adapt a knurling tool? ------- Date: Sun, 23 Mar 2003 14:16:40 -0500 From: "Mark Babiy" Subject: Re: knurling attachment I have been trying to do the same. I have had some luck knurling the nickel silver tubing using just a straight knurl on a 1/2 " tool holder, which was milled to fit the Taig tool post. Because you only want to knurl a small area I think you might be able to do this. I have had no experience with the diamond pattern, but I suggest you go to Nick Carter's site and try and build the scissors type of knurling tool. The problem with my method, is that in order to push the tool into the work, you have to put an awful lot of pressure on the headstock and I have had the tubing loosen on the jaws. The scissors tool alleviates that problem. The method I suggested does work, but it is not great. You only need to knurl a very small portion of the slide band less than and 1/8" so you don't really need to move the knurl across the work. Good luck and let us know of how it turns out. I know there are other rodmakers on this list. Mark Babiy ------- Date: Sun, 23 Mar 2003 12:26:02 -0800 From: "Nicholas Carter and Felice Luftschein" Subject: Re: knurling attachment Any knurling of tubing runs the risk of collapsing the tube or deforming it - unless it is thick, best to put a temporary plug in it when knurling. As others have said, you can straight knurl by running one knurl into the tube, although that does place stress on the lathe, and a scissors type knurler like the one I made plans for will give better results. http://www.cartertools.com/nfhome.html ------- Date: Thu, 25 Sep 2003 09:26:00 -1000 (HST) From: Tom Benedict Subject: Re: How to knurl On Thu, 25 Sep 2003, Larry Richter wrote: > The knurling wheels are bought parts, of hardened steel. The pattern > they cut is a diamond pattern. There are other patterns. A couple of days ago I was flipping through "Metalworking" by Paul Hasluck (Lindsay should still carry this one). I wound up in the section on knurling, one I hadn't really read too closely before. One page very casually said something like, "There are a variety of knurls available," and then had pictures. WOW! There were straight knurls (coining), diamond knurls, beading knurls, ones that imprinted ivy leaf patterns, etc. I figure there were thirty or forty different knurls on that page. I'm sure those are still available somehwere, right? I know MSC and Enco aren't likely to have them (I've looked), but SURELY someone still sells those things. Has anyone run across a commercially produced knurl that's got ivy leaves on it? I'm also trying to remember where I saw this article on making knurls. I'd like to say it was Guy Lautard, but I could well be wrong. The article wasn't so much talking about making diamond knurls as making things like curved knurls for doing coining or "ropework". When I first saw it, I didn't have any drill rod in my shop. Now that I've got some,I'd be very interested in trying my hand at making some custom knurls. Well... I guess before taking on the knurls I should break down and build a knurling tool. Heh! How the projects do pile up. Tom ------- Date: Thu, 25 Sep 2003 19:33:46 -0700 From: "Larry Richter" Subject: Rolls, not knurls, alas Seems like there must be knob marker knurls out there for scales. The fancy stuff still exists for jewelry work, but it takes the form of rolls instead of knurling rollers. Usually a decorative pattern or patterns are placed on a hand powered roller stand that also sizes wire and changes the thickness of soft metal sheets. The decorative wire that results from the pattern roll is usually called ring wire, one of the nicer things that it helps make. If you can find a Rio Grande Albuquerque catalog, they show beautiful detail. My big favorite were spoon rolls. A small German company figured out how to make a nesting pattern of impressions on large diameter rolls that would turn a sheet of German silver (what else?) into fully formed, separated spoons and forks in one pass. Sort of a waterfall of soup spoons. They had Krupp, which then was lackey level job shop, do their roll cutting for the prototype. It worked, Krupp stole it, made them for everybody, and got rich. WW1 and WW2 followed like clockwork. Sad. ------ Date: Fri, 26 Sep 2003 22:14:55 +0100 From: Clive Foster Subject: Re: Re How to knurl >>>So now the part that confuses me. Do the knurls line back up in the pattern pressed on the previous passes making an even pattern? I have been wondering this for a long time. I want to think that the more you knurl the less perfect looking the pattern is, if that makes sense? Thanks, Ric <<< Ric: Once you have a knurl started the pattern repeats and stays in sync as you move up and down the work-piece. Essentially the technique is like screw-cutting in that you do a full pass at each setting but, with no positive external traverse control, you rely on the knurls keying into the bit already done to hold synchronisation. You can get into trouble if the knurl pattern is not a multiple of the work-piece diameter, especially on small work. There have been various methods for calculating the right starting diameter published in the Model Engineering and Home Shop Machinist press over the years. Some are of quite daunting mathematical complexity, all are claimed to give absolutely reliable results but none, in my hands at least, seem any more reliable than just applying the knurl and seeing what happens. Note that there are two types of knurl. The traditional knurl (as previously described) is a forming tool and obviously needs considerable pressure to make it work. There are also cutting knurls available which supplement the forming action with cutting. These work with much lighter loads but, as I understand things (not having used them), need to be fed along the work-piece to perform the cutting action and so won't produce a short knurl in the middle by feeding straight in as can be done with a conventional tool. I would have thought that cutting knurls might be a better bet on the lightweight Taig. I have a surprisingly effective hand squeezed knurling tool consisting of two pivoted arms with two knurls about 1 inch apart on the lower arm and one on the top one aligned halfway between the other pair. The lower arm has a fixed bar with several pivot holes in it so that the top arm position can be adjusted to fit the work. In use it is hooked over the work piece and the arms squeezed together (like a nut cracker). A modicum of sideways force lets the tool work its way along the work-piece. Even on steel good knurls can be created quite rapidly once you have the feel for the right amount of pressure (rather less than you might expect!) to apply. I found a South-Bend Heavy 10 was the answer to all my knurling problems but, in the context of this group, that probably counts as cheating! HTH. Clive -------- Date: Fri, 26 Sep 2003 23:07:37 -0400 From: Stan Stocker Subject: Re: Re: How to knurl Hi Ric, The knurls are slightly loose on their axles, and the axles are a little bit longer than the knurl is thick. This lets each knurl settle into the groove of the previous knurling pass. ------- Date: Sat, 28 Feb 2004 20:14:45 -0800 From: "Nicholas Carter and Felice Luftschein" Subject: Re: Nick Carter's Knurling Tool question...... > I am building this as well and have a problem. In the photos it > shows the upright peice (not the upper or lower bars but the one > that is verticle) having 3 parts (3" long ) but the drawing shows > (or calls for) 2. Which is it 2 or 3? Is there any change to the > rest of the parts due to 3 parts versus 2? I've built several of these over the years and I changed my design from the one shown in the photos to the one in the drawings. You want the thickness of B to be equal to the thickness of the knurls. Sometimes three pieces of 1/8" steel stacked together exactly matches the thickness of a 3/8" wide knurl, sometimes it doesn't. By using the B-2 spacers in between the two B-1 parts, you can precisely make the thicknesses of B and the knurls equal. You could make B from one piece of steel as well, 3/8" thick adusting for the knurl width. It is better to have B be thicker than the knurl, rather than thinner, as it will bind a bit if thinner than the knurl width. Too wide and the knurl will move laterally, unless you make thin shim washers to take up the space. http://www.cartertools.com/nfhome.html ------- Date: Wed, 22 Sep 2004 12:31:53 -0700 From: "sablex~xxbadger.cx" Subject: Knurling tool to purchase? I've looked over the plans for building a Knurling tool for the Taig lathe, and I think it is a bit past my skills right now. Is there a purchasable double clamp style tool that will fit the Taig? Hopefully not too expensive:) badger ------- Date: Wed, 22 Sep 2004 16:16:45 -0700 (PDT) From: Jason Croyle Subject: Re: Knurling tool to purchase? Go to www.littlemachineshop.com They have a small knurling tool; some modification may be needed. Jason ------- Date: Mon, 24 Oct 2005 20:36:43 +0100 From: Clive Foster Subject: Re: Knurling [taigtools] Knurling is right up there with parting off as a subject which sounds easy in the printed "how to do it" page and looks easy when Mr Expert does it but promptly gathers an army of about 54 million gremlins cheer-led by the little man who lives under the bench and steels your tools when you try it yourself at home! Apparently considerable shop language is the norm until you get the hang of it. Basic problem with conventional knurls is that it's a forming and distorting process rather than a cutting one. Hence considerable force is needed. It helps a lot when the rate of forming hits the sweet spot at which the metal flows well. Frankly a Taig is no way hefty enough to generate the forces needed to make conventional push in knurls, as sold in a smart holder with the two opposed knurls close together on a pivot thingy to self centre, work well. For lightweight lathes the standard approach is a pair of knurls on opposite arms of a screw tightened clamp. Theory is to set up so the knurls are aligned on the vertical diameter of the work, set it spinning and slowly tighten up until knurl is formed. Usual problem with diamond knurling is miss-registration so you get an ugly double knurl forming. I've yet to see a convincing explanation of why this happens but many workers consider that a prime cause is starting with the wrong diameter stock. Usual explanation is by analogy with gears. Th ideal diameter apparently should be such that each knurl does a number of complete tooth steps for each turn of the stock. Obviously if its not a complete number of steps then the knurl has to slip a bit before things get lined up again. If it doesn't slip to re-register after the first turn then a second slightly offset knurl is formed on that rotation but next time round the error cancels and it goes back to the first pattern. Hence one knurl forms on the odd number turns and one on the even number ones. Theoretically you could have more than one but I guess that in practice the knurl is not coarse enough to leave room for more than two. I have seen various formulae to get the magic starting diameter but tend to be sceptical 'cos the results differ. Personally I think a major contribution to such problems is the knurls not being exactly and stably opposite on a diameter of the stock. If you think about it small errors and a bit of play could add up to all sorts of mischief. I do all my knurling with a hand held three wheel "nutcracker" type tool. Basic construction is like the old style nutcracker with two handles pivoted at one end. One handle has two knurls on it a bit under an inch apart (from memory) the other has one knurl arranged to lie between the other two. The pivot can be adjusted to change the space between the handles so that different size stock can be accommodated. To use the the beast its simply threaded over the spinning stock and squeezed. Keep everything well lubricated and use a bit of side force to pass up and down the bit to be knurled and you soon have a good result. Starting diameter of the stock does not seem to be very important although when its well out you do get considerable cutting action with lots of thin slivers coming off. Murder if you get them stick in your fingers and can mess up the job if they get stuck in the knurls. I think the main reason the tool works well is that, being hand held, its not totally rigid and follows the knurl cut rather than trying to impose the lathes will on the tool. I understand that there are also cutting type knurls which are fed in from the end and cut the pattern. I've never seen or used them but suspect that the forces involved will be much lower but you need to get starting diameters dead right for good results. HTH. Clive ------- Date: Thu, 22 Dec 2005 16:52:32 -0000 From: "Hank" Subject: Knurling tools / was Homebrew QCTP [atlas618lathe] I'd like to hear from anyone else who has a knurling tool for their 6 inch lathe. This general subject doesn't seem to come up too often and the knurling tools offered in regular tool catalogs don't seem to offer an out-of-the-box fit for our small lathes, especially if you're using one of the QCTPs. Hank ------- Date: Fri, 23 Dec 2005 08:36:47 -0600 From: "Leo Reed" Subject: Re: Knurling tools / was Homebrew QCTP [atlas618lathe] I have a knurling tool that was made for the Atlas/Craftsman 6" lathe. It was sold by Sears in the 1950's. I have used it several times. It has two knurling wheels mounted in a swiveling head. The shank fits the "lighthouse" tool post that came with the lathe. I do not like to use the tool, because it puts tremendous pressure on the lathe (especially when knurling steel), just like rolling threads. I understand there is a knurling tool that does not put this kind of pressure on the machine. It has a scissors-like arrangement that takes the pressure. If I had a need to do a lot of knurling, I would look into getting this type of device. Leo (pearland, tx) ------- Date: Fri, 23 Dec 2005 08:34:16 -0000 From: "Michael Dhabolt" Subject: Re: Knurling tools [atlas618lathe] I got the scissors style from little machine shop - less than $30 - it is mounted on a 3/8" tool stub, so it'll fit into the tool holder on your QCTP. Works great, the scissors type is much less stress on the lathe IMHO. You can crank a lot of pressure onto the rollers if you make sure they are exactly on a centerline across the workpiece. Mike ------- Date: Fri, 23 Dec 2005 10:30:04 -0500 From: "" Subject: Re: Knurling tools / was Homebrew QCTP Hank: Check my website. I use the same knurler on all three of my machines. (Atlas 6" - South Bend 9 - Grizzly 12x37) I like this style better than the pressure style (less flex). http://www.bowermachineandtool.com Earl Bower ------- NOTE TO FILE: For those of you with a strong shaper, some knurling is possible. See the "Shaping Tips" file for a conversation 10 April 2006. ------- knurling problems [sherline] Posted by: "Alan Wright" alanx~xxyahoo.com Date: Mon Sep 18, 2006 3:53 pm (PDT) This is somewhat OT, since I am not specifically having trouble with the Sherline knurling tool. However, I've had the same trouble with it in the past. In any case I'm using scissor type knurls on either of my machines which employ pairs of knurls. I've had the typical problem of the knurls making a mess instead of proper knurls. I understand that the trick is to find the right diameter of the part to correspond closely to a multiple of the knurl tooth spacing. Today I decided to measure all of my knurls carefully and get the rough value of these multiples for each one. I employed the method of turning the part down to just over the expected diameter for a good knurl, and tested the tracking of the knurl with light cuts until I got down to a size where it was close to perfect. When I went ahead and did the full knurl, what I found surprised me. Instead of getting a perfect diamond knurl, I got a perfect knurl in one angle and a finer knurl at the other angle. It dawned on me that the two knurls might not match on size (diameter), so I measured that pair and my other ones (I have coarse, medium, and fine diamond and also a straight pair). I found that all pairs were at least .004 different, and as much as .008. In addition, the knurls have or had other inconsistencies (badly drilled holes), and I guess are just the usual crappy imports. I am guessing I need to buy knurls in matching pairs, or buy a brand that is sufficiently consistent in size that this is unnecessary. Is this correct? If so, where can one buy knurls in matching pairs? If not in pairs, where to get high quality knurls to avoid this problem? thanks, Alan ------- Re: knurling problems Posted by: "toryranger" TORYRANGERx~xxwi.rr.com Date: Mon Sep 18, 2006 4:47 pm (PDT) Knurling tools designed to be use pairs of knurls should use knurls bought is sets. Most of the industrial suppliers on the net will have knurls that they sell it sets. J & L, Manhatten Supply, Penn Tool, Enco are a few names that come to mind. I have all of them bookmarked, but I;m about 1000 miles from my computer right now. Smitty ------- Re: knurling problems Posted by: "Alan Wright" alanx~xxyahoo.com Date: Mon Sep 18, 2006 5:28 pm (PDT) I wasn't able to find knurls in pairs at any of my usual places (MSC, ENCO, J&L...), but it looks like Travers has either pairs (of unknown quality, "Form Roll" brand) or high quality knurls (Dorian Tool?) to choose from. I'm still not sure which to try. Alan ------- Photos Posted ... An alternate approach to making a Rope-Knurl [sherline] Posted by: "minitool41" minitool41x~xxyahoo.com minitool41 Date: Tue Dec 26, 2006 9:03 pm ((PST)) I have posted four photos that demonstrate a very preliminary (but simple) approach to making a rounded rope-knurl. This is based on only two hours of work, but I believe the concept could work. Further, it seems to provide a means of custom-shaping the surface of the knurl (from a flat surface to a shaped profile) to fit a specific need. The knurl is cut using a conventional machine-screw tap. The number of lines on the knurl is equal to the pitch of the tap. The cut is made by feeding the face of a (soft) knurl blank into a rotating tap which is positioned perpendicular to the axis of the knurl. When the tap begins to cut into the surface, it begins to rotate the knurl (much like a worm gear) and continues to cut around the outer edge of the knurl. Since taps are quite brittle (and don't like side loads) this must be done taking very light cuts and with the use of cutting oil. The broad range of tap/pitch options might be considered to minimize breakage (ie you could use a 6-32 tap or a 10-32 and get the same number of lines on the knurl.) I didn't have a problem with rotational speed of the tap, but kept it under a few hundred rpm during the test. The brass test-piece was made using the first knurl that I produced from leaded steel. The tool was far too soft and quickly dulled at the center. However, it was clear that it could work around the sides of the rounded surface. (Note: On the very best day, my knurling results are very iffy! Using the soft knurl and lacking the correct knurl holder, it is impressive that I got anything!) Take a look at the photos and let me know if further explanations are required. John Maki Minitool http://tech.ph.groups.yahoo.com/group/sherline/photos/browse/4789 ------- Re: Photos Posted ... An alternate approach to making a Rope-Knurl Posted by: "Alan KM6VV" KM6VVx~xxSBCglobal.net Date: Wed Dec 27, 2006 8:00 am ((PST)) Hi John: Innovative use 2nd headstock for an 'A' axis! And interesting work as well. Not sure of the term "rope-knurl". I was expecting a decorative scroll on a long piece of stock. Yesterday I think it was a knurling was being demonstrated with an engraving point and CNC with an 'A' axis also. ALSO an interesting way to do the job. Now I don't need to purchase a knurling tool! I'll have to work out the code, 'tho. Alan KM6VV ------- Re: Photos Posted ... An alternate approach to making a Rope-Knurl Posted by: "Orrin" oisemingx~xxmoscow.com Date: Wed Dec 27, 2006 2:02 pm ((PST)) That is a mighty clever approach, John, and the knurl looks great! Good job. Have you seen Frank Ford's Web site? He is a luthier, but he's a whiz in the machine shop. Here is his approach to making a rope knurl: http://www.frets.com/FRETSPages/Machining/Projects/RopeKnurl/ropeknurl .html Mr. Ford's site is loaded with all sorts of interesting machine shop tricks: http://www.frets.com/FRETSPages/Machining/index.html Regards, Orrin ------- Re: Photos Posted ... An alternate approach to making a Rope-Knurl Posted by: "minitool41" minitool41x~xxyahoo.com Date: Wed Dec 27, 2006 8:19 pm ((PST)) Thanks for the feedback, Orrin. Yes, I have looked at Frank Ford's site, but was a little intimidated by the need to make an engraving tool. In fact, the idea of making a knurling tool probably originated from his site. Actually, I was trying to solve an entirely different problem when this solution hit me. I was trying to find a way to make a small scale worm gear set for a miniature tool I had in mind. The approach worked for the worm gear set, but also inspired me to use the same method to create a knurl that would wrap the sides of a rounded surface on a knob. Sometimes one problem leads diectly to a solution to an entirely different problem. John Maki ------- Re: Ok, so next question... [taigtools] Posted by: "Kristin" kd006x~xxyahoo.com Date: Sun Mar 9, 2008 3:09 pm ((PDT)) "markzemanek" wrote: > Thank for the spindle speed answer Kristin. My next question is about > using Nick's home made knurling tool in conjunction with those spindle > speeds. I thought knurling is an operation that is supposed to be > performed at slow spindle speeds...even slower than that bottom-end > speed of 525 rpm...if this is true, then is it necessary to modify > one's system somehow to slow the spindle further? Thanks in advance. > Mark Mark, I suppose Nick could best answer that, but I recall last time I Knurled it was on a lathe with back gears and very slow using the power feed. However that was probably 40 years ago so ... Might be a good reason to add a jackshaft option to get down to 100 RPM or less. I am still waiting for my secondhand Taig to arrive but I am thinking this may be in the works as I have plans to do some knurling myself. I am also keeping my eye out for a garage sale electric treadmill for the motor and speed control as that would solve all those mechanical problems. Kristin ------- Re: Ok, so next question... Posted by: "markzemanek" markzemanekx~xxyahoo.com Date: Sun Mar 9, 2008 3:20 pm ((PDT)) Kristin: You might be able to acquire a variable speed treadmill and motor for free via your local www.freecycle.org The chapter where I live actually has their site setup as a Yahoo newsgroup much like this one. You can offer items for free that may be of no service to you anymore, and likewise you can post a "Wanted" ad, in search of items you are looking for. You just can't post items requesting money or trades. It's an invaluable service to the community, on a national level. I've seen several treadmills pass through my site over the last six months or so, and may actually post a request myself looking for a variable speed motor. And lucky me lives only about a mile from my local metal recycling yard, so I won't have any problems passing along the metal I can't use. Cheers, Mark --------- Re: Ok, so next question... Posted by: "Nicholas Carter and Felice Luftschein" felicex~xxcasco.net Date: Sun Mar 9, 2008 4:30 pm ((PDT)) In aluminum you can do fine knurling at those speeds. For steels, etc, I usually just turn the chuck by hand. See our homepage at www.cartertools.com/nfhome.html ------- Re: Ok, so next question... Posted by: "Steve Blackmore" stevex~xxpilotltd.net Date: Sun Mar 9, 2008 6:55 pm ((PDT)) Why does knurling has to be performed at low speed? It's no different than any other machining operation. The rigidity of the lathe is the major consideration, not the speed it's done at. Steve Blackmore ------- Re: Ok, so next question... Posted by: "pe3hmp" pe3hmpx~xxhotmail.com Date: Sun Mar 9, 2008 7:10 pm ((PDT)) It's because you are not cutting but moving material. Mark ------- Re: Ok, so next question... Posted by: "markzemanek" markzemanekx~xxyahoo.com Date: Mon Mar 10, 2008 7:09 am ((PDT)) I've been digging around the net looking for an explanation too, why it's suggested knurling is best done slowly. In the book "Machine Trade Shop Secrets," page 191, (http://tinyurl.com/3dvbhc ) it states, however that the parameters aren't overly critical. Here are some excerpts. Mark "Start feeding the tool slowly along the length of the shaft. Feeding slowly on the first pass helps maintain proper tracking of the rollers in the previously laid grooves." ...and... "Use feeds,speeds and pressures you are comfortable with. These parameters are not overly critical. Start with slow to moderate settings then increase them as you see fit. A lot depends on the rigidity of your part and setup." ------- Re: Ok, so next question... Posted by: "Tony Jeffree" tonyx~xxjeffree.co.uk Date: Mon Mar 10, 2008 7:50 am ((PDT)) ...and that article doesn't agree with you... I quote: ". Use feeds, speeds and pressures you feel comfortable with. Start with slow to moderate settings and then increase them as you see fit. A lot depends on part rigidity and setup. In areas where the knurl comes in shallow, you can dwell and concentrate the tool in that area to help balance groove depth." Roughly translated as, you can knurl as fast as you like, the limiting factors being your skill/experience and the rigidity of the setup. I strongly suspect that single wheel tools don't work for you for similar reasons - to get a good knurl with a single wheel you need a rigid setup. I wouldn't attempt to use one on a Taug for that reason. In the next para it talks about lube being important because it is a material displacement technique, but no-where does it mention needing slow speed because of material displacement. Regards Tony ------- Re: Ok, so next question... Posted by: "mojogrisgris" mojogrisgrisx~xxyahoo.com Date: Mon Mar 10, 2008 1:30 pm ((PDT)) I have only knurled brass before but IIRC we used a low speed but were really aggressive in the feed into the part being knurled. This was on large LeBlond lathes though and the small micro lathe might not like that so much. I just remember feeding the tool into the part pretty fast. Now that I think about it the reason it was so fast may have been to prevent work hardening the piece since you aren't removing any metal, just displacing what's there into the knurl pattern. As with everything, I am sure it all depends on what the material is been used. Mojo ------- Re: Knurling [taigtools] Posted by: "markzemanek" markzemanekx~xxyahoo.com Date: Sun Mar 16, 2008 7:48 am ((PDT)) > elmer miller wrote: > > Hi gang: A newbie type here While our good guy Nick shows us how > > to MAKE a Kurling tool I cant find any details on how to use it. I > > know what it for but how do I get it to do dat??? Where do you get > > wheels??? Nicholas Carter wrote: > Buy knurls before you build. Every industrial supplier has them, > MSC, Enco, etc. As for use, slowest speed, tighten a bit, lots of > oil...experiment. > See our homepage at www.cartertools.com/nfhome.html Has anybody here actually made one of Nick's knurling tools? If so, I'm just wondering what it may have cost you to make, because... Littlemachineshop sells a scissor's type knurler for $39.95. This seems like a really good deal to me, especially considering it comes with three sets of wheels...coarse, medium, and fine. That in itself may make it worth the "price of admission." http://tinyurl.com/yu2xfv Mark -------- Re: Knurling Posted by: "Daniel Fuller" fullerdjx~xxtx.rr.com Date: Sun Mar 16, 2008 8:38 am ((PDT)) I made a knurling tool to Nick's design. It works fine. I bought the wheels from Enco. If you need to buy everything, then it will cost about 1/2 to 2/3 of the price of the LMS knurler. Just depends on whether you want to make your tools or buy them. That is for you to decide. As far as using the knurler, I have just put it in the tool holder and knurled (slow speed). I did not worry about the exact measurement of the knurl cutters vs. the diameter of the round to be knurled. My results are not professional, but it has come out good enough for me. Some people are "detail people" and some are "get out of my way, here I come." You decide what works for you. Dan Fuller Carrollton, Texas ------- Knurler [atlas_craftsman] Posted by: "Michael White" dallashotrodpartsx~xxyahoo.com Date: Tue May 27, 2008 3:20 pm ((PDT)) I found a Knurler in with all the tools that came with my Craftsman 12x36. The markings on it are: Armstrong, Chicago #1040 tool holder. It looks similar to the other tool holders but with a round end and 2 rollers. Ive seen one of these before at various machine shops I wandered into. I tried it on a 6" long piece of 1/2"x1/4" wall DOM tube. I also tried it on a 6" piece of 3/4"sch 40 pipe. The tool made a very nice pattern in both. Im not sure of the terminology but I engaged the lever that moves the tool holder. Very nice smooth sharp grooves. I added motor oil a few drops at a time. On that note I will try mixing WD-40 with some light motor oil and see if I need to thicken or thin it as the jog demands. Any further help on that is appreciated. I may have said, I have never owned a lathe before. I have however seem them used many times. I also think it can and will come in handy on what I'm building. I was surprised that the pattern is the same on different diameter tube/pipe. Im guessing that it does the same on just about any size tube/pipe? Forgive me gentlemen if I ask a lot of questions. thanks very much Michael White Dallas Hotrod Parts www.dallashotrodparts.com ------- Knurler Posted by: "catboat15x~xxaol.com" catboat15x~xxaol.com Date: Tue May 27, 2008 10:20 pm ((PDT)) Knurling can be tricky at times. The ideal is that it is like thread cutting, that is a definite relationship between the knurls and the diameter of the work. So each revolution of the work and knurl stay "in step" Not really a hard and fast rule, but sometimes you get a "smeared" knurl that is usually the problem; if possible reduce the diameter of the work a bit and try again. ------- Re: Knurler Posted by: "jerdalx~xxsbcglobal.net" Date: Wed May 28, 2008 5:20 am ((PDT)) > The ideal is that it is like thread cutting, that is a definite > relationship between the knurls and the diameter of the work. So > each revolution of the work and knurl stay "in step" Most machinists seem to agree that that is not true... for diamond knurl. For straight knurling, it is more "real". However, there is nearly always a diameter that works which is close to the diameter of the rod, and will occur when pressing in the knurl. A knurl which is 0.030 pitch between points will have "perfect diameters" approximately every 10 thou, or 5 thou on the radius. As you press in the knurl, you will pass SEVERAL of those diameters between "just touching" and 'fully impressed" knurling. Remember also that you are not "removing" , but actually "displacing" material, so the knurling "grows" about as far as you press in the wheel. Diamond knurls seem to "slide" on the slope of the knurling a little as they turn and line up, since the knurling is angled. Straight knurls can't do so as easily. JT -------