PEEK Plate

PEEK is the baseline high-performance thermoplastic: the one to reach for when a part has to hold strength, chemical resistance and dimensional stability at temperatures where ordinary engineering plastics have given up. Tensile strength is 16,000 psi at yield on a 650,000 psi modulus, flexural strength is 26,000 psi on a 600,000 psi flexural modulus, compressive strength is 20,000 psi at 10% strain and hardness is Rockwell M99. It runs continuously at 480F with short excursions to 572F, melts at 633F, and takes up almost no water - 0.02% in 24 hours.

It is machined into seals and back-up rings, bushings and bearings, pump and valve components, manifolds, wafer carriers and semiconductor fixturing, aerospace brackets and medical instrument parts. Natural stock is FDA, USDA and 3A-Dairy compliant, the flammability rating is UL 94 V-0 and it passes FAR 25.853 at 3 mm. Three things to know before specifying it. Heat deflection temperature at 264 psi is 320F, well below the 480F continuous rating, because stiffness falls away above the 302F glass transition even though the part survives. Prolonged heat embrittles it - more than half the tensile elongation is lost after 10,000 hours at 392F. And it is expensive, so cut-to-size is usually the right way to buy it.