GB T 901 is the governing dimensional standard for stud / threaded rod. This page sets out the scope of the standard, reproduces the full size table it specifies, and lists the DIN/ISO/ASME cross-references commonly cited in datasheets and drawings.
GB T 901 — Scope
GB T 901 is "Double end studs — Metal end 1.25 d". GB/T 901 is the Chinese national adoption of the same document.
Material, property class, surface finish and packaging are governed by separate documents — ISO 898-1 and ISO 898-2 for mechanical property classes, ISO 4042 for electroplated finishes.
Tolerance & Product Grades
GB T 901 does not divide stud / threaded rod — iso / din (series 154) into product grades. Tolerances are given as limits on the individual dimensions in the table.
Where a general-tolerance class is cited on the drawing instead, it applies to the dimensions not otherwise toleranced.
Dimensions Specified by GB T 901
| Thread size | Pitch (mm) | Length L (mm) | Engagement depth bm (mm) | Material | Reference standard |
|---|---|---|---|---|---|
| M6 | 1.0 | 50 | 8 | Cl. 8.8 alloy steel | DIN 939 / GB/T 901 |
| M8 | 1.25 | 60 | 10 | Cl. 8.8 alloy steel | DIN 939 / GB/T 901 |
| M10 | 1.5 | 80 | 15 | Cl. 8.8 alloy steel | DIN 939 / GB/T 901 |
| M12 | 1.75 | 100 | 18 | Cl. 8.8 alloy steel | DIN 939 / GB/T 901 |
| M14 | 2.0 | 120 | 21 | Cl. 8.8 alloy steel | DIN 939 / GB/T 901 |
| M16 | 2.0 | 150 | 24 | Cl. 8.8 alloy steel | DIN 939 / GB/T 901 |
| M20 | 2.5 | 180 | 30 | Cl. 8.8 alloy steel | DIN 939 / GB/T 901 |
| M24 | 3.0 | 200 | 36 | Cl. 8.8 alloy steel | DIN 939 / GB/T 901 |
| M30 | 3.5 | 240 | 45 | Cl. 8.8 alloy steel | DIN 939 / GB/T 901 |
| M36 | 4.0 | 280 | 54 | Cl. 8.8 alloy steel | DIN 939 / GB/T 901 |
Equivalent Standards
Where direct equivalents exist (ISO ↔ DIN, ISO ↔ ASME), they are listed on the parent Stud / Threaded Rod — ISO / DIN (Series 154) page.
Always confirm against the dimensions on this page, since some "equivalent" standards differ in tolerances and head geometry.
Companion Standards
GB T 901 controls only the geometry of stud / threaded rod — iso / din (series 154). The mechanical strength is set by ISO 898-1 (bolts, screws and studs) or ISO 898-2 (nuts); the surface finish is governed by separate finish standards such as ISO 4042 for electroplating. For corrosion testing, the relevant document is ISO 9227 (neutral salt spray).
Custom manufacturing · Made to drawing
Need a bolt to this standard in a non-standard size?
Parts built to GB T 901 are already in the catalog, so a special is usually a variation on existing tooling rather than a new design — which is what keeps the cost down. Made by cold heading or hot forging.
Minimum order from 2,000 pieces; samples within 7 days of drawing approval.

