Overview
ISO 21538:2024 - "Blanks for superabrasive cutting-off wheels - Mounting and fixing bores - Building construction and civil engineering" specifies the most common dimensions and arrangements for mounting and fixing bores in blanks used for superabrasive cutting-off wheels in building and civil engineering. The third edition updates figures and adds dimensions to reflect current clamping flange interfaces. The standard ensures compatibility with the clamping flanges defined in ISO 21537‑2.
Key topics and technical requirements
- Scope and purpose: Defines standardized bore types and dimensions to ensure safe, repeatable mounting of superabrasive cutting-off wheel blanks.
- Bore types: Five centre-bore configurations are covered - Type A (centre bore without hole circle), B, C, D, and E (various combinations of hole circles for driving pins and mounting).
- Dimensional data: Detailed values for centre-bore diameters, pitch diameters for countersunk bores and through holes, drive hole diameters and countersink depths are provided in Table 1 (dimensions in millimetres, general tolerances per ISO 2768‑1).
- Drive-hole placement rules: Minimum spacings are specified - at least 14 mm radial and 30 mm tangential between drive holes; a minimum of 20 mm radial between pitch circles.
- Countersink and through-hole limits: Countersinks are permitted on one side only, with up to two different countersink pitch diameters; two through boreholes are permitted in addition.
- Designation format: Provides a standard way to designate blanks (example format shown in Clause 5), e.g., “Mounting bore ISO 21538 - C 900 × 60 × 100/120”.
Applications
- Standardizes blanks for superabrasive cutting-off wheels used in:
- Building construction (masonry, precast, façade work)
- Civil engineering (concrete cutting, road and bridge maintenance)
- Ensures interchangeable mounting interfaces between wheel blanks and clamping flanges, improving safety, machine compatibility and supply-chain interoperability.
Who should use this standard
- Manufacturers of superabrasive wheel blanks and clamping flanges
- Machine builders and tool designers specifying mounting interfaces
- Procurement and quality engineers in construction and civil engineering firms
- Standards committees and conformity assessors working with abrasive tool safety and dimensions
Related standards
- ISO 21537‑2 - Clamping flanges for superabrasive cutting-off wheels (building and construction) - referenced for flange dimensions
- ISO 2768‑1 - General tolerances for linear and angular dimensions
Keywords: ISO 21538:2024, superabrasive cutting-off wheels, mounting bores, fixing bores, clamping flanges, building construction, civil engineering, ISO 21537-2, wheel blanks, dimensions, drive holes.