Nylon 6/6 30% Glass Filled Rod

Thirty percent glass fibre turns nylon 6/6 from a wear material into a structural one. Stiffness roughly triples - tensile modulus reaches 1,200,000 psi and flexural modulus 1,100,000 psi against 425,000 and 450,000 for the unfilled grade - flexural strength rises to 26,000 psi and compressive strength to 19,000 psi, with Rockwell R122 hardness. The headline number is thermal: heat deflection temperature at 264 psi is 380F against roughly 200F unfilled, so it carries load at temperatures where plain nylon is already creeping.

It is machined into structural brackets, housings, manifolds, pump and valve bodies and machine parts that need to hold shape under load and heat rather than slide against steel. Continuous service is 220F and the melting point is 500F, and moisture pickup drops to 0.7% in 24 hours because the glass does not absorb. Three real limitations. Elongation falls to about 6%, so it is brittle next to unfilled nylon and cracks rather than yields - avoid sharp internal corners. The glass is abrasive to the mating part and to your tooling, which is why it makes a poor bearing material despite being a strong one. And it is not food-contact compliant. Note too that published stiffness varies by about 50% between manufacturers of this grade, so a figure from one mill will not match another.