Specification summary of ISO as applied to custom machined component: the dimensions the standard controls, the tolerance and product grades it defines, the full specified size range, and the equivalent DIN/ISO/ASME designations.
ISO — Scope
ISO specifies the dimensions and tolerances of custom machined component — iso / din (series 115). 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, alongside the related ISO / DIN 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
| Size designation | Outer diameter / width (mm) | Length / height (mm) | Bore / thread (mm) | Material | Reference standard |
|---|---|---|---|---|---|
| Size 1 | 10 | 20 | 6 | C45 carbon steel | GB/T 1804-m |
| Size 2 | 12 | 25 | 8 | C45 carbon steel | GB/T 1804-m |
| Size 3 | 16 | 32 | 10 | C45 carbon steel | GB/T 1804-m |
| Size 4 | 20 | 40 | 12 | C45 carbon steel | GB/T 1804-m |
| Size 5 | 25 | 50 | 16 | C45 carbon steel | GB/T 1804-m |
| Size 6 | 32 | 63 | 20 | C45 carbon steel | GB/T 1804-m |
| Size 7 | 40 | 80 | 25 | C45 carbon steel | GB/T 1804-m |
| Size 8 | 50 | 100 | 30 | C45 carbon steel | GB/T 1804-m |
Equivalent Standards
Where direct equivalents exist (ISO ↔ DIN, ISO ↔ ASME), they are listed on the parent Custom Machined Component — ISO / DIN (Series 115) page. Always confirm against the dimensions on this page, since some "equivalent" standards differ in tolerances and head geometry.
When to Specify ISO
Choose ISO for international engineering work and OEM supply where ISO standards are the contractual reference. It is the default modern specification for custom machined component — iso / din (series 115).

