MB Lock Washer – Secure Locking for Bearings & Shaft Nuts MB Lock Washers are specially designed locking washers used in combination with KM lock nuts to prevent loosening due to vibration, shock, or rotational forces. They are commonly used to lock bearings, sleeves, and shaft-mounted components in place, ensuring safety and operational reliability. Manufactured from high-quality carbon steel or stainless steel, MB Lock Washers offer excellent strength, flexibility, and wear resistance. Each washer features inner tabs that fit into the shaft keyway and outer locking tabs that are bent into the nut slots after tightening, providing a positive mechanical lock.