Internally Threaded Dowel Pin — GB/T 120.1 / ISO 8735 (Series 100) manufactured to T 120.1 follow a specific scope. This page summarizes that scope, lists every dimension the standard fixes, and points to the most common cross-references.
T 120.1 — Scope
T 120.1 specifies the dimensions and tolerances of internally threaded dowel pin — gb/t 120.1 / iso 8735 (series 100). 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
T 120.1, alongside the related GB/T 120.1 / ISO 8735 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 T 120.1
| Nominal diameter d (mm) | Length L (mm) | Internal thread | Material | Reference standard |
|---|---|---|---|---|
| 4 | 16 | M3 | Alloy steel | ISO 8736 / GB/T 120 |
| 5 | 20 | M4 | Alloy steel | ISO 8736 / GB/T 120 |
| 6 | 24 | M4 | Alloy steel | ISO 8736 / GB/T 120 |
| 8 | 30 | M5 | Alloy steel | ISO 8736 / GB/T 120 |
| 10 | 40 | M6 | Alloy steel | ISO 8736 / GB/T 120 |
| 12 | 50 | M8 | Alloy steel | ISO 8736 / GB/T 120 |
| 16 | 60 | M10 | Alloy steel | ISO 8736 / GB/T 120 |
| 20 | 80 | M12 | Alloy steel | ISO 8736 / GB/T 120 |
Equivalent Standards
Where direct equivalents exist (ISO ↔ DIN, ISO ↔ ASME), they are listed on the parent Internally Threaded Dowel Pin — GB/T 120.1 / ISO 8735 (Series 100) page. Always confirm against the dimensions on this page, since some "equivalent" standards differ in tolerances and head geometry.
Companion Standards
T 120.1 controls only the geometry of internally threaded dowel pin — gb/t 120.1 / iso 8735 (series 100). 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).