42 mm bore bearings
9 models with a 42 mm (1.654 in) bore across 1 bearing type, outside diameters from 47 to 57 mm. Tables are grouped by type; open a model for full specs and equivalents.
9 models 47–57 mm OD range 1 brand
| Model | Series | d (mm) | D (mm) | B (mm) | Brand | Seal | Clearance | C (kN) |
|---|---|---|---|---|---|---|---|---|
| K42X47X17 | K | 42 | 47 | 17 | SKF | open | CN | 20.9 |
| K42X50X20 | K | 42 | 50 | 20 | SKF | open | CN | 33.6 |
| NK42-20 | NK | 42 | 52 | 20 | SKF | open | CN | 27 |
| NK42-30 | NK | 42 | 52 | 30 | SKF | open | CN | 39.1 |
| RNA4907 | RNA-49 | 42 | 55 | 20 | SKF | open | CN | 31.9 |
| RNA4907-2RS | RNA-49 | 42 | 55 | 20 | SKF | 2RS | CN | 27 |
| RNA6907 | RNA-69 | 42 | 55 | 36 | SKF | open | CN | 48.4 |
| NKI42-20 | NKI | 42 | 57 | 20 | SKF | open | CN | 29.2 |
| NKI42-30 | NKI | 42 | 57 | 30 | SKF | open | CN | 41.8 |
Selecting a 42 mm bore bearing
The bore fixes the shaft, not the bearing capacity. At 42 mm the catalog spans 47–57 mm outside diameter: the light sections suit compact housings and moderate duty, while the larger ODs use bigger rolling elements and carry substantially more load. Select first by the required dynamic load rating C for the calculated L10 life, then by available radial space.
For a rotating inner ring a k5 shaft seat with an H7 housing is the usual starting point; an interference fit plus thermal growth consumes internal clearance, so C3 is the common industrial default rather than CN. Sealed variants (-2RS, -ZZ) trade a small amount of speed for contamination protection and maintenance-free operation — compare the sealed and open versions of the same envelope before substituting one for the other.
Frequently asked questions
What bearings have a 42 mm bore?
This index lists 9 verified bearing models with a 42 mm (1.654 in) bore across 1 bearing type, from 47 to 57 mm outside diameter. Open any model for the full specification table, seal/clearance options and graded cross references.
How do I choose between the 47–57 mm OD options for a 42 mm shaft?
On a fixed 42 mm bore, a smaller outside diameter means a lighter section for limited housing space and moderate load; a larger OD with a wider ring carries more radial and axial load and lasts longer at the same duty. Compare the C dynamic load rating in each model table, then match seal type, internal clearance (CN/C3/C4) and precision class to the actual mounting and operating temperature.
What shaft fit and bore code apply to 42 mm bearings?
A 42 mm bore on a rotating inner ring normally uses a k5 shaft seat with an H7 housing bore (verify against the catalogue for heavy or stationary-ring duty). Bore diameters below 20 mm follow the 10/12/15/17 mm exception table rather than code × 5.