VDI and BMT Driven Tool Holders

A driven tool holder mounts in the turret of a CNC lathe so the machine can mill, drill, tap and cut side features in the same setup. The part never leaves the chuck, so the second-operation setup and its positioning error both disappear — which is why demand keeps growing as turn-mill machines spread.

Confirm the turret interface before choosing a type

Two systems dominate. VDI is a cylindrical shank to DIN ISO 10889 — commonly VDI20, 25, 30, 40 and 50. BMT is bolted to the turret face — BMT45, 55, 65, 75 and 85. Two machines can both say BMT65 and still locate differently, so send the machine make, model and turret specification and we will match it. The filter above browses by machine brand.

Common types

Axial (straight): tool in line with the spindle, for face drilling and tapping
Radial (90°): tool perpendicular to the spindle, for side milling and cross drilling
Adjustable angle: set within a range, for angled holes and faces
Multi-spindle: several tools in one unit, fewer index moves
High-speed and through-coolant: for small-diameter tools or centre coolant

Three things people get wrong

Torque and speed have to match the actual cut, not the highest number on the sheet; the coolant arrangement (flood, through-tool, high pressure) has to match the machine; and the gear ratio sets the usable speed range — get it wrong and tool life drops noticeably.

Mongtec Precision supplies tooling for CNC lathes and turn-mill centres, covering around 6,000 specifications across the VDI and BMT interfaces. We also inspect and repair driven tool holders of any brand. Not sure what your machine takes — send the model and the operation and we will confirm it.published at mongtec-tools.com.