SKF7008CP4DGASuper-Precision Angular Contact Ball Bearing, Universally Matchable Pair, 40 x 68 x 15 mm, 15 Degree Contact Angle, Light Preload, Phenolic Cage

Product Description

What this part is

SKF 7008 CD/P4ADGA is a super-precision single-row angular contact ball bearing supplied as a universally matchable pair. Bore 40 mm, outside diameter 68 mm, width 15 mm per bearing, 30 mm across the pair. Contact angle 15°, machined phenolic cage, open on both faces.

Decoding the designation

7008 is the ISO 70 dimension series at a 40 mm bore. CD sets the 15° contact angle with SKF’s standard machined outer-ring-guided phenolic cage. P4A is ISO dimensional tolerance class 4 carried at class 2 running accuracy, equivalent to ABEC 7. DGA denotes a set of two bearings, flush ground so they mount in any arrangement, with GA light preload built in.

What these specs mean in practice

A 15° contact angle favours speed and radial stiffness over thrust capacity; the 25° ACD variant reverses that trade. GA is the lightest of SKF’s three preload grades at roughly 60 N per pair, which keeps heat generation and drag low and suits high-speed grinding and milling spindles. Limiting speed is 19 000 r/min on grease and 32 000 r/min on oil. Basic dynamic load rating is 16.8 kN for a single bearing and 27.2 kN for the preloaded pair; static rating is 11 kN single and 22 kN paired.

Quantity and configuration

Two bearings, one matched pair. Flush ground faces allow back-to-back, face-to-face or tandem mounting, with GA preload established once the rings are clamped.

Fitting notes

Preload on a universally matchable set comes from the ground ring faces, so both inner rings and both outer rings clamp solid against their seats and against each other. The mounting marks on the outer ring diameters align to keep the ground offsets in register. Preload takes the place of a radial internal clearance class on a set like this.

Interchange guidance

Direct equivalents at 15° with a phenolic cage and light duplex preload include Fafnir 2MM9108WI CR DUL and FAG B7008C.T.P4S.UL. NSK 7008CTRDULP4Y matches the geometry and preload at a tighter P4Y running accuracy. The 7008 ACD/P4ADGA shares the envelope at a 25° contact angle, a related size rather than a substitution.