DuPont Vespel SP thrust washers are suitable for continuous temperatures of up to 290°C (554°F) and short-term peaks up to 480°C (896°F). Able to withstand high pressure and speed loads in lubricated applications, the SP-21 and SP-22 abrasion-resistant, low-friction washers are used by ZF Passau for step-less, hydrostatic power-split Eccom continuously variable transmissions on agricultural machinery. The planet wheels rotate against the washers, separating from the planet wheel carrier to reduce friction and abrasion and improve reliability of the transmission. The tribological properties of the material lead to lower friction losses vs. metal-to-metal pairings, improving start/stop performance. Vespel washers feature a stud that locks into place with a corresponding recess in the cast-iron planet-wheel carrier to ensure that relative movement only occurs between the planet wheel and thrust washer and eliminating the need for additional finishing of the metal surface.