Knurling Question

[prasad]

Prasad, I tried to post pics of my knurler before but was unable to do so until Nelson and Robert got to work on the problem. Now it seems to work and I can show you a simple tool I made for my Sherline lathe. It is mounted to the rear of the cross slide and will transfer to my larger lathe by changing the mount. This knurler has produced beautiful knurls in mild steel, stainless, aluminum, brass and Delrin. In most cases, it will create a full-pattern knurl on the first pass if I do my job.

View attachment 113315 View attachment 113316 View attachment 113317

I hope this gives you some ideas if you decide to make one of your own.

Edit: I forgot to add that it will knurl from zero out to 2-1/8" OD and despite having a hex shaped shank on the main screw, it tightens with simple hand pressure. Cost was almost nothing except the knurls - just stuff I had laying around the shop.

Thank you Mike. Pictures are clear to me. This will be one of my projects. I have printed the photos for reference later. Thanks again
Prasad

 

[mikey]

Yup, you're welcome. Sorry it took so long, and I hope this gives you some ideas for making your own.

 

[mikey]

I tried to find a good pic of a knurl but I don't have many pics and can't find them anyway. I do have an unusual one that comes from George H Thomas. It is called a Square Knurl. I made a true square knurl but the corners of the pattern felt a bit sharp on the fingers so I cut a hex shape instead and it feels nice but with a good grip. The main knurl is a simple straight knurl, which is then cross cut with a 60 degree tool; spacing between the cross cuts is the same as the peak to peak distance of the straight knurl. If you cut to the same depth as the straight knurl you get a square pattern. If you cut less than that depth you get a hex as seen here.



The straight knurl is cut in a single pass to full depth and it is important to do this so you produce a clean pattern with which to work. A scissors knurler will do this quite well. For a less busy pattern, use a knurl with fewer teeth.

Anyway, thought I would share.

 

[prasad]

I tried to find a good pic of a knurl but I don't have many pics and can't find them anyway. I do have an unusual one that comes from George H Thomas. It is called a Square Knurl. I made a true square knurl but the corners of the pattern felt a bit sharp on the fingers so I cut a hex shape instead and it feels nice but with a good grip. The main knurl is a simple straight knurl, which is then cross cut with a 60 degree tool; spacing between the cross cuts is the same as the peak to peak distance of the straight knurl. If you cut to the same depth as the straight knurl you get a square pattern. If you cut less than that depth you get a hex as seen here.

View attachment 113343

The straight knurl is cut in a single pass to full depth and it is important to do this so you produce a clean pattern with which to work. A scissors knurler will do this quite well. For a less busy pattern, use a knurl with fewer teeth.

Anyway, thought I would share.

Mikey

Great idea. I want to try it. I will share the photo if result is good.

-Prasad

 

[Wreck™Wreck]

A hard steel roll spinning on a hard steel pin will result in the two parts welding together when one component transfers a bit of its metal to the other part due to friction and heat. The carbide pin is extremely smooth and much harder than the roll, so there is less chance of the parts setting up.

Not exactly true, there are many applications employing hard steel on hard steel interfaces (rolling element bearings, ball, tapered roller or roller, drill bushings, automotive ring and pinion gear trains for example), a small amount of lubrication is required however. I have never used a knurling tool that used carbide pins, this does not mean that they do not exist.

 

[NightWing]

Not exactly true, there are many applications employing hard steel on hard steel interfaces (rolling element bearings, ball, tapered roller or roller, drill bushings, automotive ring and pinion gear trains for example), a small amount of lubrication is required however. I have never used a knurling tool that used carbide pins, this does not mean that they do not exist.

And I have never used a knurling tool that didn't have carbide pins. Use anything you like.

You can't compare ball or roller bearings to knurling tools because ball and roller bearings have point contact with their respective races and they roll rather than slide, as is the case of a knurl wheel sliding over a pin with almost 100% contact. Yes, steel pins might work for a while but if you want longevity, then carbide pins are the answer. I owned a manufacturing company for 22 years and we knurled and thread rolled thousands of pieces on production equipment. Carbide pins were the only answer.