Pollak 21-517 Precision Ball Switch – Normally Closed (NC), .250" Blade Terminals

Heavy-Duty Precision for International and Industrial Applications

The Pollak 21-518 Precision Ball Switch is a high-performance sensing solution engineered for the rigorous demands of the heavy-duty trucking and agricultural industries. This Normally Open (NO) switch is a direct replacement for the International Harvester (IH) 425057C1, ensuring OEM-level reliability and fitment.

Specialized Fitment & Reliable Connectivity Unlike standard 9/16 thread switches, the 21-518 features a larger 3/4-16 thread size and specialized pin terminals. These pins are designed to integrate seamlessly into specific vehicle wiring harnesses, providing a secure electrical connection that resists vibration and environmental wear.

Built for Extreme Performance Pollak’s precision ball switches are designed to survive the harshest operating conditions. With an operating temperature range of -40°F to +250°F, this switch is ideal for high-heat environments like transmissions and engine blocks. Its rugged construction ensures a mechanical life of up to 1,000,000 cycles, significantly reducing maintenance intervals and downtime.

Key Specifications:

• Circuitry: Normally Open (NO)

• Termination: Pin Terminals

• Direct Replacement: Fits IH 425057C1

• Thread Size: 3/4-16

• Hex Size: 7/8"

• Voltage Rating: 5.0 - 24.0 VDC

• Operating Temperature: -40°F to +250°F (-40°C to +121°C)

• Cycle Life: 500,000 Electrical / 1,000,000 Mechanical

• Design: Encapsulated and assembled with O-ring for a leak-proof seal.