For Housed (Pillow Block) Bearing — ISO / DIN (Series 121), ISO 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.
ISO — Scope
ISO specifies the dimensions and tolerances of housed (pillow block) bearing — iso / din (series 121). 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
| Shaft size (mm) | Housing length (mm) | Total height (mm) | Bolt center distance (mm) | Bolt size | Reference standard |
|---|---|---|---|---|---|
| 15 | 90 | 38 | 65 | M10 | ISO 113 / GB/T 7813 |
| 20 | 108 | 42 | 75 | M10 | ISO 113 / GB/T 7813 |
| 25 | 127 | 47 | 90 | M12 | ISO 113 / GB/T 7813 |
| 30 | 140 | 55 | 100 | M12 | ISO 113 / GB/T 7813 |
| 35 | 162 | 62 | 115 | M14 | ISO 113 / GB/T 7813 |
| 40 | 175 | 68 | 130 | M14 | ISO 113 / GB/T 7813 |
| 50 | 205 | 75 | 150 | M16 | ISO 113 / GB/T 7813 |
| 60 | 250 | 85 | 180 | M16 | ISO 113 / GB/T 7813 |
| 80 | 300 | 105 | 220 | M20 | ISO 113 / GB/T 7813 |
Equivalent Standards
Where direct equivalents exist (ISO ↔ DIN, ISO ↔ ASME), they are listed on the parent Housed (Pillow Block) Bearing — ISO / DIN (Series 121) 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 housed (pillow block) bearing — iso / din (series 121).