Overview
ISO 691:2005 is an international standard that specifies tolerances for wrench and socket openings used in assembling screws and nuts with metric width across flats dimensions. Developed by the International Organization for Standardization (ISO), this standard ensures precision and consistency in manufacturing assembly tools such as wrenches and sockets. It provides defined minimum and maximum deviations from nominal dimensions, facilitating compatibility and performance in tightening applications.
By aligning the tolerances with those of screws and nuts detailed in ISO 4759-1, ISO 691:2005 supports the production of reliable, high-quality tools suitable for general use. This contributes to enhanced efficiency and safety in mechanical assembly and maintenance work worldwide.
Key Topics
- Tolerances for Wrench Openings: Specifies minimum and maximum deviations for wrench and socket openings based on nominal metric widths.
- Tool Types Covered:
- Open wrenches
- Box wrenches (closed)
- Socket wrenches (closed)
- Nominal Dimension Ranges: Applies to a wide range of sizes from 2 mm to over 210 mm in width across flats.
- Tolerance Classes:
- Class 1: Used exclusively for wrenches, tighter tolerance for more precise fit.
- Class 2: Allowing slightly broader tolerances, mainly for box and socket wrenches without material removal finishing.
- Integration with ISO 4759-1: Tolerances are derived considering the dimensional requirements of corresponding screws and nuts to ensure compatibility.
Applications
ISO 691:2005 is essential for manufacturers and users involved in:
- Tool Manufacturing: Ensuring assembly tools meet international tolerance standards for durability and fit.
- Mechanical Assembly: Providing standardized wrench and socket openings leads to consistent, efficient tightening and loosening of metric fasteners.
- Quality Control: Implementing precise dimensional guidelines improves the interchangeability and performance of tools in automotive, machinery, and construction industries.
- Maintenance Operations: Facilitating proper tool selection and use for repair and assembly processes involving metric screws and nuts.
The standard's precise guidelines minimize risks of fastener damage and tool wear, optimizing safety and operational reliability.
Related Standards
- ISO 4759-1: Tolerances for bolts, screws, studs, and nuts, which define the dimensional requirements for these fasteners.
- ISO 272: Specifies width across flats for hexagon products, supporting the sizing standards for fasteners.
- ISO 1703: Provides designation and nomenclature for assembly tools for screws and nuts to ensure standardized terminology.
These complementary standards ensure a coherent system for fastening components and tools, enabling global consistency in engineering and manufacturing processes.
Keywords: ISO 691:2005, wrench tolerances, socket openings, assembly tools, metric screws, metric nuts, ISO fasteners standards, tool manufacturing tolerances, wrench socket compatibility, mechanical assembly tools, tightening tools, ISO general use tolerances.
Open preview (PDF)Assembly tools for screws and nuts — Wrench and socket openings — Tolerances for general use