MPNbase

18 mm bore bearings

8 models with a 18 mm (0.709 in) bore across 1 bearing type, outside diameters from 24 to 32 mm. Tables are grouped by type; open a model for full specs and equivalents.

8 models 24–32 mm OD range 2 brands

Needle Roller Bearings (8)

Model Series d (mm) D (mm) B (mm) Brand Seal Clearance C (kN)
HK1812 HK 18 24 12 SKF open CN 7.92
HK1812FM HK 18 24 12 NTN open — 8.3
HK1816 HK 18 24 16 SKF open CN 11.2
HK1816-2RS HK 18 24 16 SKF 2RS CN 7.92
HK1816F HK 18 24 16 NTN open — 11.8
NK18-16 NK 18 26 16 SKF open CN 12.8
NK18-20 NK 18 26 20 SKF open CN 16.1
RPNA18-32 RPNA 18 32 16 SKF open CN 12.8

Exact-dimension interchange groups at 18 mm bore

These d×D×B envelopes at a 18 mm bore are shared by several series or brands — the starting point for a dimensional cross reference:

Selecting a 18 mm bore bearing

The bore fixes the shaft, not the bearing capacity. At 18 mm the catalog spans 24–32 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 j5 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 18 mm bore?

This index lists 8 verified bearing models with a 18 mm (0.709 in) bore across 1 bearing type, from 24 to 32 mm outside diameter. Open any model for the full specification table, seal/clearance options and graded cross references.

How do I choose between the 24–32 mm OD options for a 18 mm shaft?

On a fixed 18 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 18 mm bearings?

A 18 mm bore on a rotating inner ring normally uses a j5 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.