Specification summary of GB as applied to slotted round nut: the dimensions the standard controls, the tolerance and product grades it defines, the full specified size range, and the equivalent DIN/ISO/ASME designations.
GB — Scope
GB specifies the dimensions and tolerances of slotted round nut — gb/t 812 (series 069). 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 812 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) | Outer diameter D (mm) | Nut height m (mm) | Slot width (mm) | Slot depth (mm) | Reference standard |
|---|---|---|---|---|---|---|
| M10x1.0 | 1.0 | 18 | 8 | 3 | 2 | GB/T 812 / DIN 1804 |
| M12x1.25 | 1.25 | 22 | 8 | 3 | 2 | GB/T 812 / DIN 1804 |
| M16x1.5 | 1.5 | 28 | 8 | 4 | 2.5 | GB/T 812 / DIN 1804 |
| M20x1.5 | 1.5 | 34 | 10 | 4 | 2.5 | GB/T 812 / DIN 1804 |
| M24x1.5 | 1.5 | 40 | 10 | 5 | 3 | GB/T 812 / DIN 1804 |
| M30x1.5 | 1.5 | 48 | 12 | 5 | 3 | GB/T 812 / DIN 1804 |
| M36x1.5 | 1.5 | 58 | 12 | 6 | 3 | GB/T 812 / DIN 1804 |
| M48x1.5 | 1.5 | 72 | 15 | 6 | 4 | GB/T 812 / DIN 1804 |
| M60x2.0 | 2.0 | 90 | 18 | 7 | 4 | GB/T 812 / DIN 1804 |
| M80x2.0 | 2.0 | 115 | 20 | 8 | 5 | GB/T 812 / DIN 1804 |
| M100x2.0 | 2.0 | 140 | 22 | 10 | 5 | GB/T 812 / DIN 1804 |
Companion Standards
GB controls only the geometry of slotted round nut — gb/t 812 (series 069). The mechanical strength is set by ISO 898-1 (bolts and screws) or ISO 898-2 (nuts); the surface finish is governed by separate finish standards (e.g. ISO 4042 for electroplating). For corrosion testing, the relevant document is ISO 9227 (neutral salt spray).
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 slotted round nut — gb/t 812 (series 069).