... material, HRC52 ER nut -Taper 30 degree thread -With Patent products -G6.3 dynamic balance -ISO9001:2008 ... Type A and M ER Nut With G6.3 Dynamic BalancingMaterial: SNCM-220 steel, with high aseismicity.Hardness ... tolerance is 4H.Feature: With G6.3 dynamic balancing, suitable for rpm10,000, and with patent.Not: please using ... LM785940 Hardware Products Type A and M ER Nut With G6.3 Dynamic Balancing