Nylon 6/6 Hex Bar

Extruded nylon 6/6 is the general-purpose machining nylon and the one most shops reach for first. Of the unfilled nylons it is the hardest and most rigid, and it has the highest melting point at 500F: tensile strength is 12,000 psi at yield on a 425,000 psi tensile modulus, flexural strength is 15,000 psi on a 450,000 psi flexural modulus, compressive strength is 12,500 psi at 10% deflection and hardness is Rockwell M85 (R115). It runs dry against steel at a 0.25 dynamic coefficient of friction with a published limiting PV of 2,700 psi-ft/min, which is why it ends up in so many unlubricated bearings and wear parts.

It is machined into bearings, bushings, wear strips, gears, sprockets, rollers, sheaves, guides and insulators across conveyor, packaging, agricultural and general machinery work, and natural stock is FDA, USDA, 3A-Dairy and NSF Standard 61 compliant. Maximum continuous service in air is 210F. Two limitations matter in practice. Nylon takes up water - 0.30% in 24 hours and 7.0% at saturation - and grows as it does, so allow for movement in wet or humid service and machine close-tolerance parts from conditioned stock. And heat deflection temperature at 264 psi is only 200F despite that 500F melting point, so it creeps under load well below the temperature the melt figure suggests. Strong acids and strong alkalis attack it.