AKA: Acetal, POM, polyacetal.
Nylon based I think.
Good machining characteristics, used in engineering for its low abrasion/friction characteristics for fixturing machine parts, gears.
FYI, POM has nothing to do with nylon. Nylon is based on an amide linkage in the polymer backbone. POM is short for polyoxymethylene. No amide linkages here.
I have seen some large parts machined from Delrin
and also some plumbing or bathroom parts molded.
It can be a very stiff and stong plastic depending
on its composition. It seems to me that I remember
Delrin 100 and Delrin 500 being available. We have
specked it out for some large ball bearing spacers
and molded cages for small rollers use in military
applications.
Delrin molds very nicely, with a relatively high but consistent shrink rate, and tends to develop sink marks. After molding, its dimensional stability is good, and it has a low friction coefficient, so it's often used for molded gears with integral plain bearings. For higher PVs, a tfe- filled version, Delrin AF, brown in color, is available.
It's available as machining stock in sheets and rounds, to substantial dimensions, and is not terribly expensive. The center of the rounds and the central plane of the sheets are marked by a thin zone of high porosity. It machines easily, giving off a faint vinegar odor.
The natural white color is attractive, and can be tinted with Rit fabric dye. It's not naturally UV resistant, so the black pigmented version should be used outdoors.
