For Internally Threaded Dowel Pin — GB/T 120.1 / ISO 8735 (Series 099), T 120.1 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.
T 120.1 — Scope
T 120.1 specifies the dimensions and tolerances of internally threaded dowel pin — gb/t 120.1 / iso 8735 (series 099). 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 099) page. Always confirm against the dimensions on this page, since some "equivalent" standards differ in tolerances and head geometry.
When to Specify T 120.1
Choose T 120.1 for international engineering work and OEM supply where ISO standards are the contractual reference. It is the default modern specification for internally threaded dowel pin — gb/t 120.1 / iso 8735 (series 099).