For use in hostile environments, custom profiles include chain and belt guides as well as related components. Typical wear-resistant materials include oil-filled UHMW, UHMW-HT for 275°F service, glass-filled PTFE for -350 to 500°F applications, oil-filled or MD-nylon, and Eratalyte TX for resistance to bleach and other harsh chemicals. Sizes range from 1.25–12 in. wide and up to 20 ft long, with tolerances to ±0.005 in.