Overview
ISO 8764-1:2004 - "Assembly tools for screws and nuts - Screwdrivers for cross-recessed head screws - Part 1: Driver tips" defines the shapes, dimensions, technical requirements and torque test methods for screwdriver tips used with cross‑recessed head screws. It covers two tip forms: PH (for form H recesses) and PZ (for form Z recesses). The standard establishes geometric profiles, inspection methods (gauges), material and heat‑treatment requirements, surface finish expectations, and torque‑resistance testing for both hand-operated and machine-operated bits.
Key Topics
- Tip forms and dimensions
- Two standardized forms: PH and PZ with sizes (e.g., 0–4) specified by figures and tables for blade diameters, angles and flute geometry.
- Axis concentricity requirement; dimensions must be met after plating if a finish is applied.
- Material, heat treatment and hardness
- Steel suitable for hardening and tempering.
- Minimum hardness: 54 HRC for hand-operated tips, 58 HRC for machine-operated tips, for a length equal to three times the nominal blade diameter from the driving end. Remaining tool sections: minimum 50 HRC.
- Test block hardness for torque testing: 62 HRC minimum.
- Inspection and gauges
- Dimensional conformity checked by direct measurement or by inspection gauges (detailed in Clause 5, Annex A and B). Gauges ensure correct penetration and profile fit to screw heads.
- Torque testing
- Defined torque test procedure using a torque‑testing device and a corresponding test block. Tips must show no fracture or permanent distortion after applying specified minimum torques.
- Test torque scales with tip diameter; hand-test formula provided (M = 0.038 × d, where d = nominal blade diameter in mm).
- Designation
Applications
- Ensures interchangeability and reliable fit of screwdriver tips with cross‑recessed screws in manufacturing, maintenance and assembly.
- Used by:
- Tool manufacturers (design, production, marking),
- Quality control and testing laboratories (inspection gauges, hardness and torque tests),
- OEMs and procurement (specifying compliant tools for assembly lines),
- Maintenance and repair operations requiring standardized driver performance.
- Keyword relevance: screwdriver tips standard, cross‑recessed head screws, PH PZ driver tips, inspection gauges, torque test methods.
Related Standards
- ISO 4757 - defines H and Z form recesses (screw head geometry) that correspond to PH and PZ driver tips.
- ISO 8764-2 - complements Part 1 by giving general requirements, blade lengths and marking rules for hand-operated screwdrivers.
ISO 8764-1 is a practical reference for anyone specifying, producing or testing screwdriver tips for cross‑recessed screws to ensure correct fit, durability and torque performance.
Open preview (PDF)Assembly tools for screws and nuts — Screwdrivers for cross-recessed head screws — Part 1: Driver tips