For sheet-metal self-tapping screw, ISO 7049 is the governing document for the dimensions listed below. Mechanical and performance requirements for this part family are set by its own standards, not by the bolt and screw property-class documents.
ISO 7049 — Scope
ISO 7049 is "Cross-recessed pan head tapping screws".
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
ISO 7049 does not divide sheet-metal self-tapping screw — gb/t 845 / iso 7049 (series 045) 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 ISO 7049
| Size | Nominal diameter (mm) | Pitch (mm) | Length L (mm) | Head diameter dk (mm) | Head height k (mm) | Reference standard |
|---|---|---|---|---|---|---|
| ST2.2 | 2.2 | 0.8 | 9.5 | 4.2 | 1.4 | ISO 7049 / GB/T 845 |
| ST2.9 | 2.9 | 1.1 | 13 | 5.6 | 1.7 | ISO 7049 / GB/T 845 |
| ST3.5 | 3.5 | 1.3 | 16 | 6.9 | 2.1 | ISO 7049 / GB/T 845 |
| ST3.9 | 3.9 | 1.3 | 16 | 7.5 | 2.3 | ISO 7049 / GB/T 845 |
| ST4.2 | 4.2 | 1.4 | 19 | 8.2 | 2.5 | ISO 7049 / GB/T 845 |
| ST4.8 | 4.8 | 1.6 | 25 | 9.5 | 2.9 | ISO 7049 / GB/T 845 |
| ST5.5 | 5.5 | 1.8 | 32 | 10.9 | 3.3 | ISO 7049 / GB/T 845 |
| ST6.3 | 6.3 | 1.8 | 38 | 12.5 | 3.8 | ISO 7049 / GB/T 845 |
Equivalent Standards
Where direct equivalents exist (ISO ↔ DIN, ISO ↔ ASME), they are listed on the parent Sheet-Metal Self-Tapping Screw — GB/T 845 / ISO 7049 (Series 045) page.
Always confirm against the dimensions on this page, since some "equivalent" standards differ in tolerances and head geometry.
When to Specify ISO 7049
Choose ISO 7049 for international engineering work and OEM supply where ISO standards are the contractual reference. It is the default modern specification for sheet-metal self-tapping screw — gb/t 845 / iso 7049 (series 045).
Custom manufacturing · Made to drawing
Need a screw to this standard in a non-standard size?
Parts built to ISO 7049 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 warm forging.
Minimum order from 2,000 pieces; samples within 7 days of drawing approval.
