Material: Acetal based (POM) technopolymer. Resistant to oils, greases and other chemical agents. Flammability class UL94-HB. Pin: Polycarbonate based (PC) technopolymer, black color (white for CLEAN execution). Flammability class UL94-V2. Adjusting boss and screw: AISI 304 stainless steel screw. AISI 303 stainless steel adjusting boss.