What is the difference between UHMW and HDPE?

1.HDPE (High Density Polyethylene) has a somewhat lower tensile strength than UHMW. It possesses excellent chemical resistance and low moisture absorption.  In terms of machining, HDPE finishes a little better than UHMW, although both materials machine well.

2.Ultra-high-molecular-weight polyethylene (UHMWPE, UHMW) is a subset of the thermoplastic polyethylene.  This results in a very tough material, with the highest impact strength of any thermoplastic presently made. UHMWPE is odorless, tasteless, and nontoxic.