For Hex Socket Dog Point Set Screw — GB/T 79 / ISO 4029 (Series 018), GB 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.
GB — Scope
GB specifies the dimensions and tolerances of hex socket dog point set screw — gb/t 79 / iso 4029 (series 018). 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
GB, alongside the related GB/T 79 / ISO 4029 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 GB
| Size | Pitch (mm) | Length L (mm) | Hex socket s (mm) | Engagement depth t min (mm) | Point diameter dp (mm) | Reference standard |
|---|---|---|---|---|---|---|
| M3 | 0.5 | 6 | 1.5 | 1.4 | 2.0 | ISO 4026-4029 / GB/T 77-79 |
| M4 | 0.7 | 6 | 2.0 | 2.0 | 2.5 | ISO 4026-4029 / GB/T 77-79 |
| M5 | 0.8 | 7 | 2.5 | 2.5 | 3.5 | ISO 4026-4029 / GB/T 77-79 |
| M6 | 1.0 | 9 | 3.0 | 3.0 | 4.0 | ISO 4026-4029 / GB/T 77-79 |
| M8 | 1.25 | 12 | 4.0 | 4.0 | 5.5 | ISO 4026-4029 / GB/T 77-79 |
| M10 | 1.5 | 15 | 5.0 | 5.0 | 7.0 | ISO 4026-4029 / GB/T 77-79 |
| M12 | 1.75 | 18 | 6.0 | 6.0 | 8.5 | ISO 4026-4029 / GB/T 77-79 |
| M16 | 2.0 | 24 | 8.0 | 8.0 | 12.0 | ISO 4026-4029 / GB/T 77-79 |
| M20 | 2.5 | 30 | 10.0 | 10.0 | 15.0 | ISO 4026-4029 / GB/T 77-79 |
| M24 | 3.0 | 36 | 12.0 | 12.0 | 18.0 | ISO 4026-4029 / GB/T 77-79 |
Equivalent Standards
Where direct equivalents exist (ISO ↔ DIN, ISO ↔ ASME), they are listed on the parent Hex Socket Dog Point Set Screw — GB/T 79 / ISO 4029 (Series 018) page. Always confirm against the dimensions on this page, since some "equivalent" standards differ in tolerances and head geometry.
When to Specify GB
Choose GB for international engineering work and OEM supply where ISO standards are the contractual reference. It is the default modern specification for hex socket dog point set screw — gb/t 79 / iso 4029 (series 018).