For Socket Head Shoulder Screw — GB/T 5281 / ISO 7379 (Series 017), ISO 7379 defines dimensions, tolerances and product grades. The sections below describe its scope, what it does NOT cover, and the equivalents across DIN, ISO and ASME.
ISO 7379 — Scope
ISO 7379 specifies the dimensions and tolerances of socket head shoulder screw — gb/t 5281 / iso 7379 (series 017). Material, property class, surface finish and packaging are governed by separate documents in the same standards family (for example ISO 898-1 for the mechanical property classes of bolts and screws).
Tolerance & Product Grades
ISO 7379, alongside the related GB/T 5281 / ISO 7379 entries on this site, specifies product grades (typically A or B for fine work and C for general engineering) and tolerance classes for the controlling dimensions. Choose the grade against the precision your application requires.
Dimensions Specified by ISO 7379
| Shoulder dia (mm) | Thread size | Pitch (mm) | Shoulder length (mm) | Head dia dk (mm) | Head height k (mm) | Reference standard |
|---|---|---|---|---|---|---|
| 5 | M4 | 0.7 | 16 | 9.5 | 5.3 | ISO 7379 / GB/T 5281 |
| 6 | M5 | 0.8 | 20 | 11.0 | 6.5 | ISO 7379 / GB/T 5281 |
| 8 | M6 | 1.0 | 25 | 13.0 | 8.0 | ISO 7379 / GB/T 5281 |
| 10 | M8 | 1.25 | 30 | 16.0 | 10.0 | ISO 7379 / GB/T 5281 |
| 12 | M10 | 1.5 | 40 | 18.0 | 12.0 | ISO 7379 / GB/T 5281 |
| 16 | M12 | 1.75 | 50 | 24.0 | 16.0 | ISO 7379 / GB/T 5281 |
| 20 | M16 | 2.0 | 60 | 30.0 | 20.0 | ISO 7379 / GB/T 5281 |
| 25 | M20 | 2.5 | 80 | 36.0 | 25.0 | ISO 7379 / GB/T 5281 |
Equivalent Standards
Where direct equivalents exist (ISO ↔ DIN, ISO ↔ ASME), they are listed on the parent Socket Head Shoulder Screw — GB/T 5281 / ISO 7379 (Series 017) page. Always confirm against the dimensions on this page, since some "equivalent" standards differ in tolerances and head geometry.
When to Specify ISO 7379
Choose ISO 7379 for international engineering work and OEM supply where ISO standards are the contractual reference. It is the default modern specification for socket head shoulder screw — gb/t 5281 / iso 7379 (series 017).