ISO 2725-1:2017

Overview

ISO 2725-1:2017 - "Assembly tools for screws and nuts - Square drive sockets - Part 1: Hand-operated sockets" defines the dimensions, designation and marking for hand‑operated square‑drive sockets with hexagonal or double‑hexagonal (bi‑hex) ends. The standard covers sockets matched to driving squares (per ISO 1174‑1) and supplies dimensional tables for square‑drive sizes from 6.3 to 25 mm. It does not include product technical performance requirements (those are in ISO 1711‑1).

Key Topics

• Scope and applicability: Hand‑operated square‑drive sockets identified in ISO 1703 (reference numbers 2 1 02 01 0).
• Dimensions and tables: Dimension data (in millimetres) provided for multiple square‑drive sizes; figures are illustrative and do not dictate specific design details.
• Tolerances: Width‑across‑flats tolerances are specified by reference to ISO 691 (manufacturers may choose deviation series).
• Form and variants: Covers hex and bi‑hex (double hex) socket forms in accordance with ISO 1174‑1.
• Designation rules: A socket designation must identify form (Hex/Bi‑hex), reference to ISO 2725‑1, square‑drive dimension, width across flats, and type (A/B). Example:
  Bi‑hex socket ISO 2725‑1, 12.5 × 10 - A
• Marking requirements: Sockets must be permanently and legibly marked with at least the manufacturer’s name or trademark and the width across flats.
• Document relationships: Technical specs relocated to ISO 1711‑1; related tolerances and driving squares referenced to ISO 691 and ISO 1174‑1.

Applications

ISO 2725‑1:2017 is used by:

• Manufacturers of hand‑operated sockets and tool sets for ensuring consistent dimensions and marking.
• Design and product engineers specifying socket compatibility with fasteners (width‑across‑flats matching).
• Quality and inspection teams verifying dimensional conformity and traceability.
• Procurement and technical buyers who need unambiguous socket designations and markings for supply contracts.
• Maintenance and assembly operations seeking interchangeability and correct tooling for hex and bi‑hex fasteners.

Benefits include improved interchangeability, accurate tool specification, and clearer inventory labeling for assembly tools and socket sets.

Related standards

• ISO 1174‑1 - Driving squares for hand socket tools
• ISO 691 - Tolerances for wrench and socket openings
• ISO 1711‑1 - Technical specifications for hand‑operated wrenches and sockets
• ISO 1703 - Designation and nomenclature of assembly tools
• ISO 272 - Fasteners - Hexagon products

Keywords: ISO 2725-1:2017, square drive sockets, hand-operated sockets, hex socket, bi-hex socket, socket dimensions, width across flats, tool marking, assembly tools for screws and nuts.