Overview
ISO 7079:2016 specifies dimensional requirements for core drills with parallel shanks and with Morse taper shanks. The standard provides metric preferred diameters and corresponding lengths (in tables), recommends right‑hand cutting drills unless stated otherwise, and aims to ensure interchangeability and consistent manufacturing of core drills used in machining operations.
Key Topics
- Dimensions and preferred sizes: Two sets of tables cover preferred diameters and the associated lengths for both parallel‑shank and Morse‑taper core drills.
- Length rules: Overall length and flute length are defined in relation to diameter ranges; permissible length variation is given as min/max within a diameter range (example provided for a 4 mm drill).
- Tolerances and machining details:
- Diameter tolerance: h8 measured near the point.
- Back taper: at the manufacturer’s discretion.
- Parallel shanks: normally supplied without a driving tenon.
- Morse taper shanks: shank dimensions conform to ISO 296 (self‑holding tapers for tool shanks).
- Pre‑finishing guidance: Recommended stock removal values by diameter range are provided to calculate pre‑finishing core drill diameters (e.g., 0.20 mm for up to 10 mm, up to 0.40 mm for 30–50 mm).
- Data mapping: Annex A links ISO 7079 designations to preferred symbols in ISO 13399 for cutting tool data exchange.
Applications
ISO 7079 is practical for:
- Tool manufacturers defining production dimensions for core drills to ensure compatibility and quality control.
- Machine shops and production engineers selecting the correct drill size and length for drilling operations and pre‑finishing.
- Procurement and quality assurance teams specifying compliant parts and checking tolerances.
- CAD/CAM and tooling data managers mapping tool attributes to ISO 13399 for digital tool management and automated tool selection.
Benefits include improved interchangeability, reduced machining errors, clearer procurement specs, and easier integration with tool data systems.
Related Standards
- ISO 296 - Self‑holding tapers for tool shanks (normative reference for Morse tapers in ISO 7079).
- ISO 13399 (all parts) - Cutting tool data representation and exchange; Annex A of ISO 7079 provides relationship mapping to ISO 13399 symbols.
Keywords: ISO 7079:2016, core drills, parallel shanks, Morse taper shanks, drill dimensions, metric drill sizes, ISO 296, ISO 13399, cutting tools, tool shanks.
