FAGHybrid Ceramic Super-Precision Spindle Bearing – 40 mm ID, 68 mm OD, 15 mm Width, 15° Contact Angle, ABEC 7/9 P4S

Product Description

What this part is

FAG HC7008-C-T-P4S-UL hybrid ceramic super-precision spindle bearing. Bore Diameter: 40 mm. Outside Diameter: 68 mm. Overall Width: 15 mm. Contact Angle: 15°. Rolling Elements: Ceramic Ball. Number Of Rows: 1. Bore Type: Straight. Closure Type: Open. Cage Material: Phenolic. Cage Type: Machined, outer-ring land-riding. Precision Class: ABEC 7 / 9, P4S. Preload: Light, universally matchable. Bearing Material: Chrome steel rings, silicon nitride balls. Series: 70. Base Number: HC7008. Unit Quantity: 1 Pc.

Decoding the designation

HC — hybrid execution: steel rings running silicon nitride ceramic balls.

70 — single-row angular contact ball bearing, ISO 10 extra-light dimension series. 08 — bore code. Bore Diameter: 40 mm.

C — 15° contact angle. The alternative in the FAG spindle range is E at 25°.

T — fabric-base laminate phenolic cage, machined and outer-ring land-riding.

P4S — FAG super-precision tolerance class, ABEC 7 dimensional with ABEC 9 running accuracy.

UL — universally matchable, light preload. Any two bearings of this designation come up to the published preload back-to-back, face-to-face or in tandem with no shims or grinding.

Searchable forms of the designation: HC7008-C-T-P4S-UL, HC7008CTP4SUL, HC7008C.T.P4S.UL, HC 7008 C T P4S UL, HC7008CTSULP4S.

What these specs mean in practice

Silicon nitride balls weigh about 40 percent of a steel ball of the same diameter, so centrifugal loading on the outer raceway falls away at speed. A hybrid bearing therefore runs faster and cooler than its steel-ball equivalent on the same envelope, and the ceramic surface resists smearing under marginal lubrication and electrical pitting on motorised spindles.

Contact Angle: 15°. The shallow angle sets the load line close to the radial plane, favouring speed and radial stiffness over thrust capacity. It is the standard machine-tool spindle angle.

Cage Material: Phenolic. A fabric-base laminate cage runs light and quiet at spindle speed and holds oil in the fabric matrix.

A single-row angular contact ball bearing carries thrust in one direction only. Two of them locate the spindle axially and set the working preload.

Mounting data

Bore Diameter: 40 mm, straight. Outside Diameter: 68 mm. Overall Width: 15 mm. Shaft shoulder diameter da 46 mm, tolerance h12. Outer ring shoulder diameter Da 62 mm, tolerance H12. Maximum recess radius ra 1 mm, ra1 0.3 mm. Minimum chamfer dimension r 1 mm, r1 1 mm.

Quantity and configuration

Unit Quantity: 1 Pc. One universally matchable single bearing, open on both faces.

Interchange guidance

Cross-Reference 1: SKF 7008 CE/HCP4A (hybrid ceramic, 15°). Cross-Reference 2: FAG B7008-C-T-P4S-UL (steel balls). Cross-Reference 3: NSK 7008CTRSULP4 (steel balls). Cross-Reference 4: NTN 7008CGD2/GNP4 (steel balls). Cross-Reference 5: Timken / Fafnir 2MM9108WICRSUL (steel balls). Cross-Reference 6: RHP 7008CTSUEP4 (steel balls). Cross-Reference 7: Koyo 7008C/P4 (steel balls). Cross-Reference 8: FAG HC7008-E-T-P4S-UL (25°). Cross-Reference 9: MRC 7008 (29°).

All nine share the 40 x 68 x 15 mm envelope. The steel-ball references match the geometry, angle and precision class but run a steel ball set, so their speed capability is lower than the hybrid ceramic set. The FAG E execution and the MRC 7008 carry different contact angles.