Abstract: At 11:30 a.m. on April 24, 2020, an employee was reinstalling the front driver side axle of a Kenworth W900 tractor truck after replacing the leaf spring. The employee requested assistance from a coworker to guide the axle's pin to set into the plate under the spring. The employee placed his left hand on the hub of the rotor and his right hand on the disc brake assembly near the spindle. As he pushed the assembly, the rotor assembly rotated causing his left ring finger to be caught into an approximate 1inch slot under the brake caliper. The employee panicked and pulled his finger out, sustaining an avulsion of the left ring finger. The employee was treated without hospitalization.