Overview
ISO 6752:2008 specifies the basic dimensions and related technical requirements for round punches with a 60° conical head and straight shank. The standard covers punches in the diameter range 0.5 mm to 20 mm, provides example material and hardness values, defines marking/ designation, and identifies typical use (primarily punching holes in steel sheet, but also applicable to other materials). ISO 6752:2008 is the second edition and technically replaces ISO 6752:1984.
Key topics and requirements
- Dimensions and geometry: Basic dimensions (point diameter D, head geometry, radius r, and shank length L) are given in the standard’s figure and detailed table covering D = 0.5–20 mm with corresponding head and length options.
- Tolerances: General tolerances apply in accordance with ISO 2768‑1 (general tolerances - tolerance class m) for linear and angular dimensions unless otherwise indicated.
- Surface condition: Surface roughness values are specified (see standard for exact micrometre values).
- Material and hardness (examples):
- Alloyed cold work steel (5 %–12 % Cr): point (60 ± 2) HRC, head (45 ± 5) HRC.
- High-speed steel: point (62 ± 2) HRC, head (52 ± 5) HRC.
- Material selection is left to the manufacturer; the listed hardness values are illustrative.
- Designation: Standardized marking format - e.g. Punch ISO 6752 - 6,3 × 80 (point diameter × length in mm).
Practical applications
- Press tooling and die-making: Specifying and manufacturing punches for blanking, piercing, and knockout operations in sheet-metal forming.
- Sheet-metal fabrication: Production environments punching holes in steel sheet and alternative materials where standardized punch geometry improves interchangeability and tool life.
- Maintenance and spare parts: Replacing or stocking punches that conform to common dimensional and hardness norms reduces downtime.
- Quality control and procurement: Ensures purchased punches meet established tolerances, hardness examples, and designation conventions for compatibility with tooling systems.
Who should use this standard
- Toolmakers and press-tool designers
- Punch/die manufacturers and tooling suppliers
- Production engineers in automotive, aerospace, appliance, and general metalworking industries
- Purchasing and quality assurance teams specifying or verifying punches and tooling components
Related standards
- ISO 2768‑1 (General tolerances - linear and angular dimensions) - referenced for tolerance class m.
- Use ISO 6752:2008 together with company tooling practices and material specifications for full implementation.
Keywords: ISO 6752:2008, round punches, 60° conical head, straight shank, punch dimensions, punching tools, punch designation, hardness values, ISO 2768.
Open preview (PDF)Tools for pressing — Round punches with 60 degrees conical head and straight shank
