Table of Contents

• When Pressure Meets Velocity
• Titans of the Wear-Grade World
• A Clear Winner Emerges
• The Competition Falters
• The Science Behind the Strength
• What Engineers Should Take Away
• FAQs

Using ASTM D-3702 as a foundation, researchers evaluated polymer thrust washers spinning non-lubricated against a smooth AISI 1018 steel counter-surface. The test spanned a 3×3 grid of conditions: three surface speeds (50, 200, and 800 ft/min) combined with pressures producing PV values up to 100,000 psi-ft/min. Surviving materials advanced to an extended round that climbed in 25,000 psi-ft/min increments until failure.

During each eight-hour run, three key metrics, wear factor, coefficient of friction, and counter-surface temperature, indicated performance: lower values indicated longer material endurance before heat and wear escalated.

• Celazole TL-60, a proprietary blend of PBI and PEEK with a dry lubricant package, tested both as injection-molded and machined parts.
• Vespel SP-21, DuPont’s graphite-filled polyimide, has long been considered a gold standard for high-temperature applications.
• Torlon 4203L, 4275, and 4435, Solvay’s polyamide-imide (PAI) family, each with different reinforcement and lubrication packages.
• PEEK 450FC30, Victrex’s carbon- and PTFE-filled wear-grade thermoplastic.

Whereas Torlon 4203L melted before completing its break-in run and PEEK 450FC30 deformed halfway through the grid, TL-60 kept moving forward. By the 125,000 PV mark at the low speed condition (2,500 psi at 50 ft/min), it stood alone; every other competitor had failed. TL-60 went on to run at 200,000 PV at this speed, under 4,000 psi of load, without catastrophic damage

TL-60’s interface temperature was about 50 °F lower than Vespel SP-21’s and nearly 200 °F lower than Torlon 4275’s at 800 ft/min, indicating resistance to melt, slower thermal breakdown, longer service intervals, and increased reliability. Injection-molded TL-60 performed nearly as well as machined stock, with only slight temperature differences at high speeds due to filler orientation.

Torlon® 4435, the highest-performing PAI grade in the evaluation, completed the initial grid but could not sustain operation beyond 100,000 PV. It melted during the first extended step at 125,000 PV, a strong result for most engineering plastics, though still significantly below the endurance demonstrated by TL-60.

Torlon® 4275, formulated for reduced friction, did not achieve the intended performance outcome; it overheated and failed at 100,000 PV. The unfilled 4203L grade was unable to complete the initial test stage.

PEEK 450FC30, a common selection for demanding wear applications, highlighted the limitations of “high-performance” classifications. It exhibited a high wear factor and melted before reaching the high-speed test condition.

Only Vespel® SP-21 approached TL-60’s performance due to its thermoset structure, which prevents melting. It reached 400,000 PV at 800 ft/min, the highest PV achieved in the study. However, this result came with significant drawbacks, including elevated friction, temperatures reaching 638 °F, and specimen fracture. SP-21 tolerated speed but not pressure.

Celazole TL-60 excels because it harmonizes all three. It wears slowly, runs cool, resists deformation, and can be molded into complex parts without losing its properties. For design teams, that means more freedom to push boundaries, whether it’s a dry-running compressor seal, a high-speed pump bushing, or a bearing that must endure both pressure and heat without lubrication.

While TL-60 commands a premium over familiar wear grades, its durability translates into longer lifespans and lower maintenance costs. In critical applications, fewer replacements often mean dramatic savings over time.