[johnmac]

I just acquired a bunch of black plastic that looks and feels like some delrin I have. How can I tell for sure that it is indeed delrin?

John

[surplusdealdude]

Delrin feels like rock.

If it's Quadrant delrin, it'll have what look like oil stain marks on an unmachined surface - other types show a ridged surface.

And it's heavy. You can tell usually by the weight.

[Geof]

Delrin is one of the most rigid plastics.

It will not soften as much with solvents like acetone or MEK that will soften PVC and ABS.

It machines a little bit like brass in the lathe when you have zero top rake and take a good cut.

If you burn a piece it creates a very acrid biting smell which is actually formaldehyde.

[johnmac]

Thanks for the replies. I will give a piece the burn test, comparing it to some known delrin.

John