JE Pistons 812-042-CS Spiro Lock Wrist Pin Retainer 0.812 In. Diameter 0.042 In. Thickness

The JE Pistons 812-042-CS is a carbon steel spiro lock wrist pin retainer designed to secure floating wrist pins within the piston pin boss. Sold individually, this retainer measures 0.812 in. in outside diameter with a 0.042 in. lock thickness, making it a precise replacement or upgrade component for high-performance engine builds.

Key Features:

• Type: Spiro Lock (spiral retaining ring)
• Material: Carbon steel
• Outside Diameter: 0.812 in. (20.625 mm)
• Lock Thickness: 0.042 in.
• Compatible Pin Diameter Range: 0.782 in. – 0.828 in.
• Sold individually (each)

Spiro locks are one of the most widely used wrist pin retention methods in performance engine building. They are installed by spreading the lock and rotating it into the retaining groove machined into the piston pin boss, and must be used with wrist pins that have a flat face and the appropriate groove. Note that spiro locks are a single-use component and cannot be reused once removed. Many performance pistons require two spiro locks per pin bore, so order accordingly.

JE Pistons has over 70 years of experience supplying precision engine components to motorsports competitors across NASCAR, NHRA, and other top-level racing series. Their wrist pin retainers are engineered to the same exacting tolerances as their forged pistons, ensuring reliable pin retention in high-RPM and high-horsepower applications.