IKO NA6904 Needle Roller Bearing with Inner Ring, 20 x 37 x 30 mm

IKO NA69 needle roller bearings are machined type caged bearings with an inner ring, in dimension series 69. This page lists 20 sizes: 12 to 90 mm bore, 24 to 125 mm outside diameter and 22 to 63 mm wide, all open (no seals).

Machined type needle roller bearings have a low sectional height and large load ratings. The outer ring is rigid and can be used even in light alloy housings. The inner ring lets the bearing run on a shaft that cannot be heat-treated and ground. The inner ring and the outer ring with cage are separable, with a small relief clearance on both sides of the inner ring raceway to make mounting easier. The allowable axial shift S between the rings is given for each size.

For the sealed version of this series, see the NA69 UU page.

Where this product is used

• Shafts that cannot be heat-treated and ground
• Compact shaft supports with a low sectional height
• Light alloy housings

Features

• Machined type caged needle roller bearing with inner ring (NA69 series), 20 sizes
• Bore 12 to 90 mm, outside diameter 24 to 125 mm
• Matching inner ring shown for each size, for shafts that cannot be heat-treated and ground
• Basic dynamic load ratings 17.1 to 178 kN, static 23 to 490 kN
• Allowable rotational speed 4,000 to 25,000 rpm (oil lubrication)

Key specifications

Available sizes

d is the bore, D the outside diameter, C the outer ring width and Fw the roller set bore diameter; C and C0 are the basic dynamic and static load ratings, and speed is the allowable rotational speed.

Selecting the right option

Choose the size with the Inside Diameter (mm) option, which is the bore of the bearing (the inner ring bore). The model number is shown with each variant and in the sizes table.

Bearings with an inner ring suit shafts that cannot be heat-treated and ground. If your shaft is hardened and ground, a type without an inner ring (RNA and TAF) can be used instead.

The assembled inner ring is shown against each size in the sizes table. The bearing and its inner ring are listed as separate parts, so request a quote to confirm what is supplied if you need both together.

Fitting and use

These bearings are not prepacked with grease, so lubricate them before use. The allowable rotational speed in the tables is for oil lubrication; for grease lubrication use up to 60% of it. The outer ring has one oil hole with an oil groove, and the inner ring has no oil hole.

Heat expansion in use, or mounting errors, can shift the inner or outer ring axially so that the rollers do not contact the raceway along their whole length. Keep any axial shift within the allowable value S given for each size in the specifications.

Ask AIMS for the shaft and housing tolerances that suit your application.

Related products

Parts that go with this range: NA69 UU: the sealed NA69 series; RNA: without an inner ring; LRT inner rings for the inner ring series; NA49 and NA48: the NA49 and NA48 series.