Round Wire Pin Locks - 21mm (pr)

The WISECO Round Wire Pin Locks in 21mm are precision-engineered retaining clips designed for high-performance engine builds and rebuild operations. These wire locks secure wrist pins in place, preventing unwanted movement during piston assembly and operation. Built for small-block and mid-range engine applications, they are an essential component for mechanics and engine builders who demand reliability in critical load-bearing areas of the engine.

Constructed from hardened steel with a 0.049-inch thickness, the Round Wire Pin Locks deliver robust holding force while maintaining minimal mass to avoid unnecessary inertia. The 21mm diameter specification matches standard wrist pin sizing across many popular engine platforms. The wire design allows for quick installation and removal without specialized tools, while the locked configuration ensures the pin stays seated under extreme combustion pressures and high RPM conditions. Each pair provides redundant security—a critical safety feature in performance and racing applications.

Engine builders, performance technicians, and motorsports enthusiasts benefit most from this product during piston and rod assembly. The locks are compatible with any engine platform using 21mm wrist pins, including street engines, track builds, and marine applications. Installation requires careful alignment of the wire ends into the grooves machined into the wrist pin; proper seating ensures maximum holding power. Whether rebuilding a high-revving small-block V8 or reassembling a marine powerplant, these locks are a proven choice for durability and peace of mind.