... ,such as BT,NT,SK,SLN ,FMB,Taper shank tool holder machine tool accessories and so on.2. The precision can reach from 0 ... .003 to 0.005mm3. Holder hardness:48-55HRC4. The protrustion length ... for mill,Machining center ,engrarving ,milling machine ,and can clamp any straight cutters and tools CNC TOOL HOLDER High precision Milling chuck BT/ER