Technical Specifications Category Specification Model 657-70 Type Pneumatic Spring-and-Diaphragm Linear Actuator Action Spring-Return (Single-Acting) Air Connection 1/4" NPT Bench Setting (Approx.) The "-70" suffix typically corresponds to a spring range where the actuator begins to move at around 6 psig and reaches full travel at approximately 15 psig. (Note: This is a common interpretation; the exact start/finish pressures should be verified.) Standard Stroke Available in various strokes (e.g., 3/4", 1-1/2", 2-1/2", 3-1/2"). The specific stroke is defined by the full model number. Spring Rate Defined by the "-70" code, providing a specific thrust output. Diaphragm Material Nitrile (Buna-N) is standard. Yoke Material Cast Iron (standard) Temperature Limits Standard: -20°F to +180°F (-29°C to +82°C).