NSK7015CTRQUMP3Super Precision Angular Contact Ball Bearing – 75 mm ID, 115 mm OD, 20 mm Width, Open, 15° Contact Angle, Medium Preload, Matched Quad Set

Product Description

What this part is

NSK 7015CTRQUMP3 super precision angular contact ball bearing set. Bore: 75 mm. Outside diameter: 115 mm. Width: 20 mm per bearing. Series: 70, ISO dimension series 10. Four single-row angular contact ball bearings, straight bore, open, supplied as one universally matched quad set.

Decoding the designation

Contact Angle: 15°. Cage: outer-ring guided phenolic. Grouping: QU, universally matched quad set. Preload: Medium, 780 N axial. Precision Grade: P3 — dimensional accuracy to P4 with running accuracy to P2. Base designation: 7015C.

What these specs mean in practice

Dynamic radial load rating (Cr) per bearing: 48,000 N. Static radial load rating (C0r) per bearing: 45,500 N. Axial stiffness at medium preload: 144 N/µm. P3 is the grade specified where rotational accuracy matters more than mounting tolerance: inner ring radial runout is held to 2.5 µm and outer ring runout to 5 µm, which is P2 territory, while the bore and outside diameter deviations stay on the P4 schedule. A 15° contact angle favours speed and rotational accuracy over thrust capacity. Medium preload raises axial stiffness above the light setting and lowers the speed ceiling in exchange. Limiting speed for a single bearing: 18,100 rpm on oil/air, 11,100 rpm on grease. As a medium-preload set of four the oil/air figure is 8,145 rpm. Maximum recommended operating temperature: 120 °C. Rings and balls are through-hardened carbon chrome bearing steel to SAE 52100.

Quantity and configuration

4 Pcs, one universally matched quad set, sold together. The set carries a V line on each outer ring outside diameter which fixes the mounting order, and as standard the V points in the direction of maximum axial capacity with the load applied to the inner ring. Bore and outside diameter sizes across the set are matched to a third of the tolerance band, and the deviation in microns from nominal is marked on the face of each ring.

Fitting notes

Shaft abutment diameter (d1): 82 mm minimum. Housing abutment diameters: D1 108 mm maximum, D2 110 mm maximum. Maximum shaft fillet radius: 1.1 mm. Maximum housing fillet radius: 0.6 mm. Effective load centre (a): 89.4 mm. Internal volume for grease charging: 27.8 cm³ per bearing. Mass: 0.64 kg per bearing, 2.56 kg for the set. Recommended shaft fit at P3 is a mean interference of 3 µm at this diameter, and a locating housing runs a mean clearance of 5 µm. For high-speed work the recommended grease fill is 20 per cent of internal volume, dropping to 10 to 15 per cent above 80 per cent of the set’s maximum speed.

Interchange guidance

Equivalents at the same contact angle, preload and quad configuration: SKF 7015 CD/P4A, FAG B7015-C-T-P4S-QUM, RHP 7015CTRQUMP3, Timken Fafnir 2MM9115WI CR QUM. The 25° version of the same envelope, 7015A5TRQUMP3, is a related size.