Overview
ISO 1085:2016 - Assembly tools for screws and nuts - Double-ended wrenches - Size pairing - defines the size pairings for double-ended wrenches with unequal nominal widths across flats. The fourth edition (2016) updates the list of paired sizes and adds the ISO 1703 reference numbers for the wrench types covered. The standard provides a definitive pairing table (Table 1) and illustrations of designations (s1 × s2) so manufacturers, purchasers and users can specify and identify double-ended wrenches consistently.
Key topics and requirements
- Scope: Applies to double-ended wrenches having two unequal nominal widths across flats. Wrench types are those identified under specific reference numbers in ISO 1703:2005.
- Size pairings: Table 1 lists standard pairings (examples range from small sizes such as 3.2 × 4 and 3.2 × 5.5 through larger combinations up to 55 × 60). Some pairings include dimensions not covered by ISO 272 for hexagon fasteners; these are indicated in the table.
- Designation: Figure 1 illustrates the conventional designations s1 and s2 for the two openings on a double-ended wrench.
- References to other standards: Nominal widths across flats refer to ISO 691 (wrench and socket opening tolerances). ISO 272 (hexagon product widths) and ISO 1703 (designation and nomenclature) are relevant background documents.
- No normative references or new definitions: The document contains no separate normative references or terms/definitions beyond direct table and illustration content.
Applications and users
ISO 1085:2016 is practical for:
- Tool manufacturers - to design and label double-ended wrench products with standardized pairings and to align product lines.
- Procurement and supply chain teams - to specify correct wrench pairings for purchase orders and reduce ambiguity in part numbers.
- Design and maintenance engineers - to select the correct wrench combinations for assemblies, maintenance kits and service tools.
- Quality and compliance departments - to verify that supplied tools conform to international pairing conventions.
- Tool set designers and retailers - to create compatible, compact sets that match common fastener sizes and reduce redundant SKUs.
Practical benefits include consistent identification, improved interchangeability, simplified inventory, and clearer specifications for assembly and maintenance operations.
Related standards
- ISO 1703:2005 - Designation and nomenclature for assembly tools (reference numbers used in ISO 1085).
- ISO 272 - Hexagon products - widths across flats (some values referenced or excluded).
- ISO 691 - Wrench and socket openings - tolerances for general use (nominal width/tolerance reference).
Keywords: ISO 1085:2016, double-ended wrenches, size pairing, assembly tools for screws and nuts, nominal width across flats, ISO 1703, ISO 272, ISO 691.
