Delrin® 570 GF20 Plate

Delrin® 570 is acetal homopolymer reinforced with 20% glass fiber, specified where a machined acetal part has to resist deflection under sustained load. Glass raises the flexural modulus to 650,000 psi and the tensile modulus to 350,000 psi, with 14,500 psi flexural strength and 7,700 psi tensile strength at yield. Heat deflection temperature climbs to 311°F at 264 psi and 329°F at 66 psi, against a 347°F melting point, with 185°F long-term and 300°F intermittent service. Creep and warpage are low, moisture absorption is 0.15% in 24 hours, and hardness is Rockwell M87.

It is used in automotive and construction hardware, fixtures and gauging, gears, cams, structural brackets, and pump and valve components that must hold their geometry under constant stress or elevated temperature. Dielectric strength is 452 V/mil and the UL 94 rating is HB. Machine with carbide tooling, since glass fiber is abrasive and surface finish will be coarser than unfilled acetal. Limitations: notched Izod is 0.90 ft-lb/in and elongation at break is 10%, so it is comparatively brittle; the exposed glass makes it a poor bearing face against soft metals; and it is attacked by strong acids and is not UV stable.