SKFSuper-Precision Angular Contact Bearing – Straight Bore, 90 mm ID, 140 mm OD, 24 mm Width, Open, 15° Contact Angle, Light Preload

Product Description

What this part is

SKF 7018-CD/P4ADGB super-precision angular contact ball bearing. Bore: 90 mm. Outside diameter: 140 mm. Width: 24 mm per bearing. Series: 70, single row. Contact angle: 15°. Precision Class: P4A. Design: high-capacity D. Open on both faces, one-piece inner and outer rings, machined cage. Country of origin as recorded on this listing: Italy.

Decoding the designation

7018 = 70 series, 90 mm bore. CD = 15° contact angle in SKF’s D design. P4A = SKF super-precision tolerance class with measuring load class A. DGB = universally matchable, light preload. Searchable forms: 7018-CD/P4ADGB, 7018CD/P4ADGB, 7018 CD P4A DGB, 7018CDP4ADGB, 7018 CDGB/P4A.

What these specs mean in practice

A 15° contact angle gives high speed capability and high radial stiffness, which is why it is the standard machine-tool spindle angle. The high-capacity D design carries 20 balls of 15.875 mm, giving a basic dynamic rating of 79.3 kN per bearing. Universal matching means the faces are ground so the bearings mount together back-to-back, face-to-face or in tandem without shims. The DGB set is built to a light preload.

Load ratings and mass

Basic dynamic load rating C: 79.3 kN (17,830 lbf) per bearing. Basic static load rating C0: 76.5 kN (17,200 lbf) per bearing. Fatigue load limit Pu: 3 kN. Mass: 1.14 kg (2.51 lb) per bearing, 2.28 kg (5.02 lb) for the pair. Reference grease quantity: 15 cm³ per bearing.

Quantity and configuration

Two pieces ship as a matched pair. Total width across the mounted pair: 48 mm. The bearings are universally ground, so the pair mounts back-to-back, face-to-face or in tandem at the factory-set light preload.

Mounting data

Shaft abutment diameter da: 97 mm minimum. Housing abutment diameters Da 133 mm and Db 136 mm maximum. Fillet radii ra 1.5 mm and rb 1 mm maximum. Chamfer dimensions r1 1.5 mm and r2 1 mm minimum. Distance from side face to pressure point a: 27.5 mm. Oil nozzle position dn: 108.7 mm. Inner ring shoulder diameter 105.4 mm, outer ring shoulder diameter 124.6 mm. As a preloaded matched pair the bearings carry no running clearance, so the internal clearance field reads N/A.

Interchange guidance

Direct equivalents at the same 15° angle and P4 class: Fafnir 2MM9118WI-DUM, NSK 7018CTRDUMP4, RHP 7018CTRDUMP4, FAG B7018C.T.P4S.DUM. Related size: 7018 ACD/P4ADGB shares the 90 x 140 x 24 mm envelope at a 25° contact angle, and 7018 CD/P4ADGA is the same bearing at extra light preload. Both are different parts rather than substitutions.