Question 1

What is the difference between BT and BBT tool holders?

Accepted Answer

BBT (Big-Plus) tool holders provide simultaneous contact on both the taper and the spindle face. This double-contact system reduces vibration and increases rigidity compared to standard BT holders.

Question 2

Can I use a CAT40 holder in a BT40 machine?

Accepted Answer

No. Although they share the same taper angle, the flange thickness and drive notch geometry are different. Using the wrong holder can damage the spindle and the tool changer arm.

Question 3

Why is HSK becoming the standard for high-speed machining?

Accepted Answer

HSK (Hollow Shank Taper) is lighter and has a short-taper design. Centrifugal forces during high-speed rotation cause the HSK shank to expand and grip the spindle tighter, ensuring superior balance and accuracy.

Question 4

How do I know which tool holder taper my CNC machine uses?

Accepted Answer

Select your machine brand and model in the Tool Holder Finder above. The inbuilt database reports the spindle taper (BT, CAT, HSK, SK, CAPTO), the retention/pull-stud standard, spindle speed and torque, and links directly to the matching tool holder category.

Question 5

What is the difference between VDI and BMT turret tool holders?

Accepted Answer

VDI (DIN 69880) uses a cylindrical shank locked by a single radial screw for quick changes, while BMT (Base Mount Tooling) bolts to a serrated turret face for higher rigidity. They are not interchangeable — always match the holder to your lathe's turret interface.

Industrial CNC Tool Holder Compatibility Finder & Technical Database

Find the right tool holder
for your machine.

Taper & Holder Library

Tool Holder FAQ

Industrial CNC Tool Holder Compatibility Finder & Technical Database

Find the right tool holder for your machine.

Taper & Holder Library

Tool Holder FAQ

Find the right tool holder
for your machine.