Overview
ISO 9524:1993 defines the functional connecting dimensions for the front faces of spindle holders on machining centres. Its purpose is to ensure interchangeability and reliable fixing of accessories by automatic tool changing devices, and to guarantee correct machine operation of electrically operated accessories, coolant feed accessories and mechanical indexing accessories (e.g., angle heads, drilling‑tapping heads, speed‑increasing gears).
Key topics and requirements
- Scope: Functional connecting dimensions for spindle‑holder front faces and accessory interfaces to enable automatic tool changer (ATC) use.
- Main accessory classes:
- Electrically operated accessories (transmitter/receiver modules)
- Coolant feed accessories (male end inserted into connector block)
- Mechanical indexing accessories (indexing ends, angle heads, gears)
- Functional dimensions: Primary dimensions include the centre distance S and face‑to‑gauge‑plane distances C, C2, C3 that control radial and axial positioning of connector blocks and accessory ends.
- Connector blocks:
- Types for electrical, coolant and indexing connections; fixed with two M8 screws and located by two pins of diameter 6 mm.
- Material requirement: connector block made from type 35 CD4 steel treated to ~1 400 MPa rupture strength or equivalent material.
- Spacer provision for shank Nos. 45 and 50 (used only where specified).
- Tolerances & fit: Type‑specific tolerances (e.g., Type 2 connector block: tolerance on S = ±0.02 mm). Coolant/indexing ends use an approximate diameter 18 mm with specified negative tolerance for secure sealing and engagement.
- Mounting & adjustability: Indexing/clamping angles of accessories must be adjustable; electrical transmitter/receiver alignment and coolant end travel are specified to ensure positive connection during automatic changing.
Applications and who uses it
ISO 9524 is essential for:
- Machine tool manufacturers designing spindle noses and ATC-compatible front faces.
- Accessory suppliers (electrical heads, coolant couplers, indexing devices) ensuring products fit a broad range of machining centres.
- Maintenance, assembly and QA teams validating interchangeability and reliable connections.
- Procurement and standards engineers specifying compliant tooling interfaces to reduce shop‑floor downtime.
Benefits include improved interchangeability, reduced integration risk for ATC systems, consistent electrical/coolant/mechanical connections and reduced machine changeover errors.
Related standards
- ISO 7388‑1 / Add.1 - Tool shanks with 7/24 taper for automatic tool changers (Shank Nos. 40, 45, 50).
- ISO 7‑1 - Pipe threads (relevant for coolant connector threads).
- ISO 9270 - Tapers for spindle noses (reference for gauge‑plane distances).
Keywords: ISO 9524, machine tools, spindle holders, machining centres, automatic tool changer, connector block, interchangeability, coolant feed, mechanical indexing.