Grooved and lock nut SKF HM 3056, Female thread: TR280x4 | Nominal diameter (metric): 280 mm

Shaft nuts are used to attach bearings to a shaft. They are also suitable for mounting bearings with a tapered bore on tapered shaft journals and adapter sleeves and make it easier to remove bearings on withdrawal sleeves. Shaft nuts are also often used to secure gears, tensioners and other machine parts on the shaft.