Overview
ISO 8688-2:1989 - Tool life testing in milling (Part 2: End milling) specifies recommended procedures for conducting tool-life tests of high‑speed steel (HSS) end mills when machining steel and cast‑iron workpieces. Intended for both laboratory and production environments, the standard focuses on test conditions where tool deterioration is mainly due to wear and provides a uniform framework for reporting, evaluating and presenting results.
Keywords: ISO 8688-2:1989, tool life testing in milling, end milling, high‑speed steel, tool‑life criteria
Key topics and technical requirements
- Scope and test types: Defines three end‑milling test types - slot milling, peripheral (tool periphery used predominantly), and end‑teeth dominated milling - and clarifies that tests are for wear‑dominated conditions.
- Workpiece specifications: Recommends reference materials (for comparability) such as steel C45 (ISO/R 683‑3) and cast iron grade 25 (ISO/R 185). Suggested test-piece geometry: minimum width 2×D and minimum length 10×D (D = cutter diameter); for D = 25 mm this implies 50 mm min width and 250 mm min length (20×D preferred).
- Tool and cutter requirements: Advises use of uncoated HSS reference tools (per ISO 4957); identifies typical HSS types used as references. Specifies tool geometry references (ISO 3002‑1 / ISO 1641‑1) and tighter tolerances where geometry is not the test variable.
- Surface and runout limits: Calls out tool surface finish limits (face R_a ≤ 1.25 µm; flank R_a ≤ 0.8 µm) and requires runout checks on mounted tools (example maximums given in the standard).
- Cutting fluid and cutting conditions: Requires cutting fluid for steel tests (casting tests typically avoid fluid); defines recommended cutting speeds, feeds and depths for tests where wear dominates, and requires clear documentation when any parameter is varied.
- Assessment, measurement and reporting: Specifies how to assess tool deterioration and establish tool‑life criteria, test planning and procedures, recording methods, evaluation (including statistical treatment) and presentation of results. Annexes include reference materials, example data sheets and statistical calculations.
Applications and users
Who uses ISO 8688-2:1989:
- Tool and cutting‑tool manufacturers comparing HSS end‑mills
- Test laboratories and R&D teams validating tool life and tool‑wear behaviour
- Production and process engineers establishing or verifying cutting data for milling steel and cast iron
- Quality and standards teams documenting repeatable test procedures and reporting
Practical use cases:
- Comparing tool grades, geometries or cutting fluids under standardized milling conditions
- Establishing recommended cutting data and wear limits for production planning
- Producing comparable tool‑life data for supplier or product validation
Related standards
- ISO 3685 - Tool‑life testing with single‑point turning tools
- ISO 1641‑1 - End mills and slot drills (dimensions)
- ISO 3002‑1 - Cutting tool geometry terminology
- ISO 4957 - Tool steels
- ISO/R 683‑3 and ISO/R 185 - Reference workpiece materials
Use ISO 8688-2:1989 to standardize end‑milling tool‑life testing and ensure comparable, reproducible results for tooling selection, process development and quality assessment.
