Overview
ISO 4028:2003 defines the international technical specification for hexagon socket set screws with dog point. The standard covers dimensional characteristics, material and mechanical-property options, tolerances and acceptance criteria for set screws with threads from M1.6 up to and including M24, and applies to product grade A items. ISO 4028:2003 is the third edition (2003) and replaces the earlier edition.
Key topics and technical requirements
- Scope and sizing
- Covers hexagon socket (Allen) set screws fitted with a dog point; thread range M1.6 to M24.
- Includes dimensional definitions (socket geometry, point form, lengths) and nominal/limit dimensions referenced in tables and figures.
- Materials and mechanical properties
- Permitted materials: carbon/alloy steel, stainless steel, and non‑ferrous metals.
- Mechanical property classes and testing referenced to related standards (ISO 898-5 for carbon/alloy steel, ISO 3506-3 for stainless steel, ISO 8839 for non‑ferrous).
- Threads and tolerances
- Surface finish and coatings
- Inspection and acceptance
- Acceptance inspection procedures described by ISO 3269.
- Gauging of hexagon sockets per ISO 23429.
- Designation
- Example format: Hexagon socket set screw ISO 4028 - M6×12 - 45H (shows thread, nominal length, property class).
Applications and who uses this standard
ISO 4028 is essential for:
- Fastener manufacturers producing hexagon socket set screws with dog point to ensure interchangeability and compliance.
- Design engineers and mechanical designers specifying secure axial positioning or locating features in assemblies.
- Quality inspectors and laboratory personnel performing acceptance checks and dimensional verification.
- Purchasing and procurement teams specifying standardized threaded fasteners in procurement documents.
- CAD modelers and production engineers using standardized dimensions to avoid fit and assembly issues.
Common applications include machine tool assembly, jigs and fixtures, transmission components, and any application needing a positive locating/stop feature provided by a dog point.
Related standards (selection)
- ISO 261, ISO 965‑2, ISO 965‑3 (threads)
- ISO 898‑5, ISO 3506‑3, ISO 8839 (mechanical properties)
- ISO 4759‑1 (tolerances, product grades)
- ISO 4042, ISO 10683 (coatings)
- ISO 3269, ISO 6157‑1, ISO 23429 (inspection, surface, gauging)
Keywords: ISO 4028, hexagon socket set screws, dog point, set screw standards, M1.6–M24, product grade A, fasteners, thread tolerances.
