Machining nylon bar stock

Iv been trying to reduce 32mm nylon bar stock to 20mm. Its all I have. I have never worked with this material before. The finish is horrible. How do you machine this stuff. Speeds and feeds Iv tried every thing the work piece is awful.

Machining PTFE I used high speeds ( 800rpm on 90mm dia) and quite hig feeds ( sorry I don't have numbers) and a very sharp tangential cutting tool in HSS. Nylon could easily be similar.

Hi Dave,

As Andy say, use high speeds and a sharp tool. Here is a link that may be of interest:

*** Link***

Thor

Use a razor sharp knife tool and you should not have any probs.

Rik

Hello Dave,

The secret is to use a really heavy feed, the tooling isn't critical, I have machined nylon with tipped tools, brazed carbide and HSS with equally good results.

Reducing 32 mm stock to 20 mm can be done in two passes, a 4mm roughing cut followed with a 2 mm finishing cut. Work speed is about 500-600 rpm and the 'swarf' justs flows over the tool in a satisfying ribbon.

Coolant for deep drilling, where the risk of hole closure around the drill is present seems to favour WD40 or a paraffin based liquid. For drilling keep pulling out the drill to clear the flutes and when it starts to smoke let things cool down a bit..

Trying to shave off the final thou or so doesn't work well as the stuff is fibrous and just tears.

I hope that helps

Brian

There is a photo on the "What did you do today page of the pile of swarf that landed 4 feet away

Edited By ANDY CAWLEY on 12/06/2015 10:27:00

I've done lots of turning and milling of Nylon. With sharp tools it machines very easily and gives a good finish.

Turning produces very long ribbons that get everywhere, so I traverse the workpiece in bursts to break the ribbon before it gets too long and wraps around the chuck. Blunt tools tend to rub and produce sufficient heat to locally melt the Nylon, which results in a very poor finish. This is particularly true when drilling large diameter holes. Be careful when using slitting saws; the saw can easily generate sufficient heat to weld the Nylon to the saw, with obvious results.

I give up on it the finish is rubbish no matter what I do. I'm going to buy some 20mm barstock I'm wasting to much time and material trying to get it right.