PTFE
PETP is polyethylene terephtalate, available in sheet and rod from Allplastics. It is one of the hardest industrial plastics and exhibits high mechanical and creep strength, together with low thermal expansion, very good sliding properties and high dimensional stability as it is virtually unaffected by ambient moisture. PETP is especially recommended for uses with close tolerance, precision moving parts which require relative low friction and are subject to sustained high loadings and wear. PETP is easily machined, can be glued, is non toxic and has FDA approval.