This listing is for 4 piece/s.Lock nuts are used to locate bearings onto a shaft. Additionally, they can be used to mount bearings with a tapered bore onto tapered shaft seats and adapter sleeves, and to dismount bearings from withdrawal sleeves. They are frequently used to secure gears, belt pulleys and other machine components. Lock nuts have to be secured to prevent unintentional loosening, by either a locking device that engages a keyway in the shaft or key slot in the adapter sleeve, or a locking mechanism integrated in the nut. KM lock nuts, also known as shaft or withdrawal nuts, are designed to be used with lock washers. They feature four equally spaces slots located around their circumference to accommodate a hook or impact spanner. Lock Nut Features Simple, stable and reliable fastening element. Wide range of sizes. Easy to mount and dismount. Specifications d3: 58 mm B: 9 mm d1: 50 mm b: 6 mm h: 2.5 mm