About HDPE|High-density
polyethylene. Tough, chemically inert, FDA-approved for food contact, and inexpensive. Softer and more flexible than most engineering plastics. Used for cutting boards, tank liners, chemical containment, and food processing components. Machines easily but the softness can cause chatter on thin sections. Use sharp tools with high positive rake. Compare to
UHMW (higher molecular weight, better wear resistance, similar applications) and
Polypropylene (similar chemical resistance, slightly stiffer).