Overview
ISO 7388-1:2007 specifies the dimensions and designation of tool shanks with a 7/24 taper for automatic tool changers. The standard covers shank forms A, AD, AF, U, UD and UF (each with up to two optional additions) used on machines with automatic gripping systems that transfer tools between the magazine and the spindle. Dimensions are given in millimetres and the shanks are designed to fit spindle noses per ISO 9270 to ensure interchangeability.
Key topics and technical requirements
- Shank forms covered: A, AD, AF, U, UD, UF - including allowances for coolant holes and data media.
- Dimensional system: All dimensions and tolerances in millimetres; tolerancing principles per ISO 8015 and general tolerances per ISO 2768‑1 and ISO 2768‑2.
- Shank sizes: Standard shank numbers include common sizes (for example 30, 40, 45, 50, 60) with detailed dimensional tables in the standard.
- Coolant provisions:
- AD / UD: optional through hole (e.g., for centric inner coolant supply) - permitted only when hole diameter does not exceed the core diameter for the retention-knob thread.
- AF / UF: optional pair of holes at the flange rear for inner coolant; auxiliary bore design at manufacturer’s discretion but must be sealed to withstand up to 5 MPa operating pressure.
- Data medium: Provision for adding a data medium (tool-ID chip) with specified fitting position relative to the cutting edge; dimensional details given in the standard.
- Material and heat treatment: Guidance to ensure adequate strength, hardness, case depth (or through-hardening), toughness and wear resistance for tool shanks.
- Designation format: Prescribed labeling (example) - “Tool shank ISO 7388-1 - A 40 - D” (where “D” denotes fitted data medium).
Applications and practical value
- Ensures mechanical interchangeability of tool shanks in CNC machines with automatic tool changers.
- Standardizes coolant and data interfaces, enabling integrated coolant-through tooling and tool‑ID systems.
- Supports consistent tool magazine and spindle nose design, reducing downtime and simplifying procurement.
- Useful for specifying replacement tooling, verifying compliance, and designing automated manufacturing cells.
Who uses this standard
- Machine tool manufacturers and spindle designers
- Tooling and cutting-tool suppliers
- CNC integrators and automation engineers
- Toolroom managers, maintenance teams, and procurement specialists
Related standards
Keywords: ISO 7388-1:2007, tool shanks, 7/24 taper, automatic tool changers, shank forms A AD AF U UD UF, spindle noses, coolant-through tooling, data medium.
Open preview (PDF)Tool shanks with 7/24 taper for automatic tool changers — Part 1: Dimensions and designation of shanks of forms A, AD, AF, U, UD and UF