The threaded rod of the belt oil filter wrench is usually made from stainless steel because it is strong and able to withstand wear. Stainless steel is a steel alloy with a minimum of 10.5% chromium. It does not readily corrode, stain or rust.
PVC (Plastic)
PVC (polyvinylchloride) is a very commonly-used plastic. PVC is used for the handle, pad and belt because it is resistive to abrasion, lightweight and has excellent mechanical strength and toughness.
These parts being light makes it easier for users to move when removing filters. The strength and toughness of PVC makes it able to withstand wear and have a long working life.