FAGSuper-Precision Angular Contact Ball Bearing – 35 mm Bore, 55 mm OD, 10 mm Width, 15° Contact Angle, P4S Class, Light Preload

Product Description

What this part is

A FAG super-precision single-row angular contact ball bearing, 35 mm bore, 55 mm outside diameter, 10 mm width. Open, straight bore, machined phenolic laminate cage, P4S tolerance class, universally ground for light preload. The same bearing is designated 71907-TG-P4 in the older FAG scheme and B71907-C-T-P4S-UL in the current Schaeffler scheme.

Decoding the designation

719 is the ISO dimension series and 07 the bore code, giving a 35 mm bore. The B prefix marks the super-precision spindle-bearing execution. C is a 15° contact angle. T and TG both denote the machined phenolic laminate cage. P4S is the tolerance class, running to ABEC 7 dimensional limits with ABEC 9 running accuracy. UL is the universal grinding with light preload: two bearings of this designation come together back-to-back or face-to-face at a defined light preload with no shims or ground spacers, and any number can be stacked in tandem.

What these specs mean in practice

The 719 dimension series is the extra-light, narrow cross-section family — a 10 mm width across a 35 to 55 mm envelope. That thin section is what lets a designer stack two, three or four bearings into a short spindle nose while keeping the shaft large. A 15° contact angle is the high-speed, low-thrust end of the angular contact range: it reaches a higher limiting speed and runs cooler than a 25° bearing in the same envelope and carries correspondingly less axial load. P4S is a super-precision grade specifically aimed at running accuracy, holding radial and axial runout tighter than standard P4.

Cage material and speed

The phenolic laminate cage is machined from cotton-fabric-reinforced phenolic resin, land guided. It is light and self-lubricating, which is what makes it the standard choice for very high spindle speeds with oil-air or oil-mist lubrication. Phenolic sets a lower continuous temperature ceiling than a machined brass cage.

Quantity and configuration

1 Pc. Single bearing, supplied loose. The UL grinding means a second bearing of the same full designation pairs with this one at the factory-set light preload.

Mounting data

Bore form: straight, for an interference-fit spindle seat. Outer ring location: bored housing against a square shoulder. Thrust face: identified by the high shoulder on each ring. Back-to-back (DB) arrangement: the stiffest, with moment capacity. Face-to-face (DF) arrangement: tolerates more misalignment. Tandem (DT) arrangement: sums thrust in one direction.

Interchange guidance

Timken/Fafnir 2MM9307WI is the same 35x55x10 mm 15° super-precision envelope, its 2MM prefix denoting the 15° angle. NSK 7907CTYNSULP4 and SKF 71907 CD/P4A are the same series, angle and class. Cage material and the preload letter must match across every bearing in a set. A 71907 in an A5, B or E execution carries a different contact angle, and a 71907 at P5 or P6 is a different tolerance class, so both are related sizes rather than interchanges. The wider 7907 in the 79 dimension series is a different cross-section.