BT40 Precision ER Metalworking Toolholding Tool Holders for CNC Milling Machines These BT40 tool holders are metalworking toolholding BT holders with keyway, widely used with VMC (vertical machining center), cnc milling machine, cnc machining center, etc. BT40 ER Tool Holders Features: 1, All BT40 tool holder cone comes with pull stud and collet nut 2, BT40 tool cone precisionâ?¤ AT3, 7:24 3, BT40 ER collet chucks with AA class high precision ER collet, beat accuracyâ?¤ 0.005mm; when clamp cutters, totally beat accuracyâ?¤ 0.008mm 4, Very smooth inner cone surface 5, Harden surface, last for long time use 6, G2.5 balance test 7, Wearproof screw thread, more loading/unloading times. 8, 20CrMnTi material, carbon-nitrogen co-permeation, enhance the hardness, abrasion performance, fatigue hardness. Carburized depth> 0.8mm RicoCNC also supplies other high quality CNC tool holders and spare parts accessories. HSK, ISO, SK, BT, CAT toolholder fork fingers, ER, SYOZ, EOC, SK, C type collets, collet nuts, spanner wrenches, tool holder tightening fixtures, CNC router spares and much more. Official website: cncsparetools.c0m ricocnc.c0m Welcome your inquiry.