BT 40 High Precision ER tool holders are mainly used for CNC milling machines.
- Made from alloy steel hardened to 54 - 56rc
- Tool holders balanced to G2.5 at 25,000 RPMs
- Coolant-through capability
- Concentricity is less than .0002 at collet face
- Rear thread for pull stud is 5/8-11
- Spring collet not included
