-SNCM-220 material, HRC52 ER nut -Taper 30 degree thread -With Patent products -G6.3 dynamic balance -ISO9001:2008 approval Hardware ... °, once molding processing, ensure precision, thread tolerance is 4H.Feature: With G6.3 dynamic balancing, suitable for rpm10,000, and ... , outside diameter is small than standard nut, thread is different with type A.Other ER nut: type UM/RD, type KM ...