Repeated autoclave.
Hydrolysis resistant.
Amber transparent.

PSU (Udel): $60-90/kg, 174 °C HDT, transparent amber, slightly less tough. PPSU (Radel): $100-150/kg, 207 °C HDT, same color family, much tougher (doesn't crack under impact). PPSU is premium grade — use when impact resistance matters (baby bottles, tools subjected to drop) or higher temperature needed. PSU adequate for most autoclavable lab and medical applications.

Polycarbonate: cheap ($8-12/kg), great clarity, impact resistant. Problem: hydrolyzes in hot water — not truly autoclavable (10-20 cycles max). PSU: more expensive ($60-90/kg), slight amber tint, survives 1000+ autoclave cycles. For reusable autoclavable medical applications: PSU wins. For consumer optical/impact applications: polycarbonate wins.

Sulfones can stress-crack when exposed to certain solvents under stress. Common offenders: acetone, methylene chloride, some cleaners. Post-machining annealing at 160 °C for 2 hours relieves internal stress, dramatically improves chemical resistance. Design considerations: avoid sharp internal corners, avoid thin sections, test specific cleaning chemistry. Our PSU/PPSU parts are annealed as standard practice.

Machines similar to polycarbonate — soft, cuts cleanly. Sharp carbide tooling, air coolant (water coolant can cause stress-cracking), climb milling, avoid flood coolant. Typical tolerance ±0.05 mm easily achieved. For optical surfaces, diamond polishing or vapor polishing after CNC. Annealing after machining is standard for stress-relief.

PSU: 170 °C continuous, 180 °C peak short-term. PES: 190 °C continuous. PPSU: 180 °C continuous, 200 °C peak. All three survive standard autoclave cycles (121 °C / 15 psi / 20 minutes). For higher-temperature service (above 200 °C continuous), switch to PEI (Ultem) or PEEK.

PSU: 1-2 week lead time. PPSU: 2-3 weeks. Medical-grade with documentation: 3-4 weeks. Custom colors: 3-4 weeks. FR grades: 2-3 weeks. For rush, standard natural/amber PSU often available from stock.