SWT/N series SWT/N series is locked by applying 4 to 6 high-strength flat screw to support the end surface, with the steel’s elasticity, the thread is deformed to be locked. The external dimension is close to and can be interchanged with F-type nut. N-type nut is applicable for installation where the nut is easily loosened and the space is limited. Its locking capacity is larger than F-type nut by more than 2 times. Material: 42CrMo,45#, 40Cr Hardness: HRC28°—32° Thread Precision: ISO4H Run Out: 0.005mm