ISO 4026 covers the dimensional requirements for swing bolt. Reproduced below: the complete size table, the tolerance grades, and the companion and equivalent standards referenced when ordering to this document.
ISO 4026 — Scope
ISO 4026 specifies the dimensions and tolerances of swing bolt — gb/t 77 / iso 4026 (series 020). 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
ISO 4026, alongside the related GB/T 77 / ISO 4026 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 ISO 4026
| Thread size | Pitch (mm) | Ring outer dia D (mm) | Ring wire dia (mm) | Total length L (mm) | SWL (kg, axial) | Reference standard |
|---|---|---|---|---|---|---|
| M8 | 1.25 | 20 | 8 | 36 | 140 | DIN 580 / GB/T 825 |
| M10 | 1.5 | 25 | 10 | 45 | 230 | DIN 580 / GB/T 825 |
| M12 | 1.75 | 30 | 12 | 54 | 340 | DIN 580 / GB/T 825 |
| M16 | 2.0 | 35 | 14 | 63 | 700 | DIN 580 / GB/T 825 |
| M20 | 2.5 | 40 | 16 | 72 | 1200 | DIN 580 / GB/T 825 |
| M24 | 3.0 | 50 | 20 | 90 | 1800 | DIN 580 / GB/T 825 |
| M30 | 3.5 | 60 | 25 | 108 | 3200 | DIN 580 / GB/T 825 |
| M36 | 4.0 | 72 | 30 | 126 | 5000 | DIN 580 / GB/T 825 |
Equivalent Standards
Where direct equivalents exist (ISO ↔ DIN, ISO ↔ ASME), they are listed on the parent Swing Bolt — GB/T 77 / ISO 4026 (Series 020) page. Always confirm against the dimensions on this page, since some "equivalent" standards differ in tolerances and head geometry.
When to Specify ISO 4026
Choose ISO 4026 for international engineering work and OEM supply where ISO standards are the contractual reference. It is the default modern specification for swing bolt — gb/t 77 / iso 4026 (series 020).