VDI and BMT Turret Analysis

When use CNC mill-turn lathe, there are two mounting options for live tool holders, VDI(Verein Deutscher Ingenieure) or BMT(Base Mount Tool).


VDI has been considered the most widely used on turret worldwide because it has been released for over 20 years, The tool is held in place by a mating part with teeth that is housed inside the turret…when an Allen wrench is used to tighten the locking screw, located on the face of the turret, the mechanism applies clamping pressure that holds the tool securely in place. The holder is kept from twisting by a pin that is located on the mounting surface of the turret.
The VDI tool holder needs to indicate the straightness during mounting, by twisting the screw to verify the precision, you can adjust the straightness to whatever you want.




BMT is the newest technology for Mill Turn machine and it is more rigid solution. When mounting the tool holder to turret, operator uses 4 screws to tighten the tool holder, which is located and further secured with locating keys present on the turret face. These keys eliminate the need for indicating the toolholder to straighten it…which is most often necessary with VDI toolholders.
Operator does not need to adjust the straightness for BMT toolholder, overall precision is based on the precision of the toolholder, and which is not adjustable.



Here is the comparison for VDI and BMT Turret.

VDI Advantage
  • Only one screw to tighten the holder, it is easy to install, and faster setup for operator

  • Lower Investment upfront, the toolholder cost is cheaper than BMT toolholder.

  • Operator can adjust the straightness and precision of the holder.

BMT Advantage
  • More rigid, used for heavy duty cutting.

  • The precision of straight is fixed, operator does not need to adjust the straightness.

MYLAS is now offering both turret options for DT and DY series, and we used German brand Sauter Turret for better stability, capacity and precision for users.