Plastic Rod Stock

Acetal (Delrin) generally holds tighter dimensional tolerance over time because it absorbs far less moisture than nylon, making it the better choice for precision-fit parts. Nylon offers higher impact strength and better wear resistance in some applications, but its dimensional stability can shift as it absorbs ambient moisture, which matters in tight-tolerance bushings or gears.

UHMW has an extremely high molecular weight polyethylene structure that gives it outstanding abrasion resistance and impact strength with a very low coefficient of friction, making it a common choice for wear strips and chute liners — but it has lower stiffness and lower maximum service temperature than acetal or nylon, so it's not the right choice for rigid, load-bearing structural parts.

PTFE has the lowest friction coefficient and among the best chemical resistance of common engineering plastics, but it's relatively soft and prone to creep (cold flow) under sustained mechanical load, gradually deforming rather than holding a fixed dimension — that makes it well suited to seals and low-friction sliding surfaces but a poor choice for structural or precision load-bearing components.

Yes, if the part will directly or indirectly contact food — not all standard grades of a given plastic are FDA-compliant, so specify an FDA/USDA-compliant grade (available in acetal, UHMW, nylon and others) rather than assuming the base material is automatically food-safe.

As-extruded or as-cast rod typically holds a looser diameter tolerance than metal bar stock and often needs to be turned or ground to final size for precision fits — precision ground rod is available in some materials (notably acetal) for applications needing a tighter as-supplied diameter tolerance.