FAGNN3021KMSP5Double-Row Cylindrical Roller Bearing 105x160x41 mm Tapered 1:12 Bore Machined Brass Cage SP Precision

Product Description

What this part is

FAG NN3021-K-M-SP, a double-row cylindrical roller bearing with a tapered 1:12 bore. Two rows of cylindrical rollers run between a one-piece outer ring and a one-piece inner ring. Boundary dimensions 105 mm bore × 160 mm outside diameter × 41 mm width.

Decoding the designation

Series NN30 is the double-row cylindrical roller line in ISO dimension series 30. Bore Code: 21, giving a 105 mm bore. Bore Type: K, 1:12 tapered bore. Cage Material: M, machined brass. Precision Class: SP, FAG special precision class, dimensional tolerance to P5 with tightened running accuracy.

What these specs mean in practice

Two rows of cylindrical rollers give very high radial capacity and radial stiffness in a short width, which is why this type carries the front position on machine-tool spindles. The design is non-locating: it takes radial load only, and axial location comes from a separate thrust or angular contact bearing elsewhere on the shaft. On an NN the 1:12 tapered bore mounts directly on a matching tapered spindle journal, with no adapter sleeve involved, and the drive-up distance along the taper sets the radial internal clearance after mounting. A machined brass cage handles higher speed and temperature than a pressed cage.

Published specifications

Bore: 105 mm (4.1339 in), tapered 1:12. Outside Diameter: 160 mm (6.2992 in). Overall Width: 41 mm (1.6142 in). Number Of Rows: 2. Rolling Elements: cylindrical rollers. Cage: machined brass (M). Precision Class: SP. Arrangement: non-locating. Closure Type: open. Bearing Material: chrome bearing steel.

Quantity and configuration

1 Pc. Bearing only, mounted directly on a tapered journal.

Fitting notes

Radial internal clearance is set on assembly by how far the inner ring is driven up the 1:12 taper, measured as the reduction in clearance rather than as an axial dimension. The outer ring carries no axial load, so it sits in the housing free to float unless a locating bearing constrains the shaft elsewhere. Both rings are one piece, so the roller set and inner ring separate from the outer for mounting.

Cross-references

Current Schaeffler naming is NN3021-AS-K-M-SP, which adds a lubrication groove and holes in the outer ring. Tapered-bore precision forms from other makers: NSK NN3021KCC1P5 and NTN NN3021KC1NAP5. SKF NN 3021 KTN9/SP is the same size with a polyamide cage instead of brass. Straight-bore NN3021 forms and the NNU double-row series, with its different roller and rib arrangement, are not the same part.