Delrin® 550/511P Rod

Delrin® 550/511P is an acetal homopolymer (POM-H) produced from a nucleated resin, which develops a finer and more uniform crystalline structure through the cross-section than conventional homopolymer grades. That structure gives high stiffness with predictable machining behaviour: 10,000 psi tensile strength at yield, a 520,000 psi flexural modulus, and 16,000 psi flexural strength, backed by the fatigue endurance and creep resistance acetal is normally specified for. Friction against steel is low at 0.20 static and 0.35 dynamic, and moisture pickup is only 0.20% in 24 hours, so machined parts hold size in humid plant environments.

Typical parts include gears, cams, rollers, bushings, sprockets, valve and pump components, conveyor wear parts, and close-tolerance fittings for automotive, material handling, food processing equipment, and general mechanical work. Stock shapes turn and mill cleanly at high surface speeds with sharp, polished tooling, cut good threads, and finish to a fine surface without lubricant. Allow for a thermal expansion coefficient of 6.8 x 10-5 in/in/°F when holding tight tolerances over a temperature range. Long-term service stops at 185°F with 300°F intermittent, strong acids and oxidisers attack it, and the natural grade is not UV stabilised for outdoor exposure.