AiVibe

CNC & Precision Machining

Tool Holder (CAT, BT, HSK)

A tool holder connects the cutting tool to the machine spindle. It combines a spindle interface, such as a 7/24 steep taper or HSK hollow taper shank, with a clamping method such as a collet, hydraulic or shrink-fit chuck.

The spindle side of the holder locates in the spindle and is pulled in by the drawbar. Common interfaces are 7/24 steep tapers in the CAT, BT and SK families, which use a pull stud, hollow taper shanks (HSK) standardised in ISO 12164, which clamp on both taper and face, and polygonal taper interfaces standardised in ISO 26623. The tool side grips the cutter using ER collets (ISO 15488), side-lock holders, milling chucks, hydraulic expansion chucks or shrink-fit holders.

Holder choice affects rigidity, runout, balance, maximum speed and gripping torque, and therefore tool life, surface finish and achievable cutting data. Dual-contact interfaces that touch on both taper and face increase stiffness and axial repeatability, which is valued in high-speed and heavy-duty machining.

Holders and pull studs must match the specification of the machine's spindle and drawbar; a mismatched or worn component can compromise tool retention, so the machine OEM documentation governs selection. Tapers must be kept clean and undamaged, and holders should be checked periodically for wear, runout and balance, especially before use at high spindle speeds.

Key points

Where AiVibe comes in

AiVibe designs and manufactures the AiAmbA AI Factory: edge devices plus AI agents that let people talk to CNC, PLC and robot controllers in plain language. Agents only propose changes, and a trained operator confirms each one.

Explore AiVibe’s work in CNC & Precision Machining →

Related terms

Terms that refer to Tool Holder (CAT, BT, HSK)

Ask AiMuruga can explain Tool Holder (CAT, BT, HSK) for your plant, product or security programme, and draw how it fits.

Ask AiMurugaTalk to our team