ISO 14583 covers the dimensional requirements for torx countersunk head screw. Reproduced below: the complete size table, and the companion and equivalent standards referenced when ordering to this document.
ISO 14583 — Scope
ISO 14583 is "Hexalobular socket pan head 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 14583 does not divide torx countersunk head screw — gb/t 2673 / iso 14583 (series 023) 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 14583
| Size | Pitch (mm) | Length L (mm) | Head diameter dk (mm) | Head height k (mm) | Cross recess | Countersink angle (deg) | Reference standard |
|---|---|---|---|---|---|---|---|
| M3 | 0.5 | 20 | 5.6 | 1.65 | PH1 | 90 | ISO 7046 / GB/T 819 |
| M4 | 0.7 | 25 | 7.5 | 2.2 | PH2 | 90 | ISO 7046 / GB/T 819 |
| M5 | 0.8 | 30 | 9.2 | 2.5 | PH2 | 90 | ISO 7046 / GB/T 819 |
| M6 | 1.0 | 40 | 11.0 | 3.0 | PH3 | 90 | ISO 7046 / GB/T 819 |
| M8 | 1.25 | 50 | 14.5 | 4.0 | PH3 | 90 | ISO 7046 / GB/T 819 |
| M10 | 1.5 | 60 | 18.0 | 5.0 | PH4 | 90 | ISO 7046 / GB/T 819 |
| M12 | 1.75 | 80 | 22.0 | 6.0 | PH4 | 90 | ISO 7046 / GB/T 819 |
| M14 | 2.0 | 80 | 25.0 | 7.0 | PH4 | 90 | ISO 7046 / GB/T 819 |
| M16 | 2.0 | 100 | 29.0 | 8.0 | PH4 | 90 | ISO 7046 / GB/T 819 |
| M18 | 2.5 | 100 | 33.0 | 9.0 | PH4 | 90 | ISO 7046 / GB/T 819 |
| M20 | 2.5 | 120 | 36.5 | 10.0 | PH4 | 90 | ISO 7046 / GB/T 819 |
| M24 | 3.0 | 150 | 43.5 | 12.0 | PH4 | 90 | ISO 7046 / GB/T 819 |
Companion Standards
ISO 14583 controls only the geometry of torx countersunk head screw — gb/t 2673 / iso 14583 (series 023). 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).
When to Specify ISO 14583
Choose ISO 14583 for international engineering work and OEM supply where ISO standards are the contractual reference. It is the default modern specification for torx countersunk head screw — gb/t 2673 / iso 14583 (series 023).
Custom manufacturing · Made to drawing
Need a screw to this standard in a non-standard size?
Parts built to ISO 14583 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.

