FAGB7026E.TPA.P4.UMSuper Precision Angular Contact Ball Bearing 130 x 200 x 33 mm, 25° Contact Angle, P4 / ABEC 7 Class, Textile Laminate Cage, Universal Medium Preload

Product Description

What this part is

A super precision angular contact ball bearing in the 7026 envelope — 130 mm bore, 200 mm outside diameter, 33 mm width. This is FAG’s spindle bearing range: single row, open, universally ground, and made to the tolerance grade machine tool builders specify for main spindle positions.

Decoding the designation

B: FAG spindle bearing series, a higher-precision execution than a standard 70-series angular contact bearing. 7026: ISO boundary dimensions, 130 x 200 x 33 mm. E: 25° contact angle in FAG nomenclature. TPA: textile laminate phenolic cage. P4: super precision tolerance class, equivalent to ABEC 7. UM: universal grinding, medium preload — any two bearings of this designation clamped together produce the specified medium preload with no shims.

What these specs mean in practice

The 25° contact angle is the stiffness-biased choice in a spindle bearing. Load passes through the bearing along a line inclined 25° to the radial plane, which is what gives it real thrust capacity and a much stiffer axial response than the 15° version, FAG suffix C, of the same envelope. The trade is speed: a steeper angle makes the ball climb further up the raceway shoulder, which increases ball spin, friction and heat. A 25° angle suits a spindle whose limiting factor is deflection under cutting load rather than rpm.

Medium preload pushes the same way. It gives more rigidity and better repeatability under load than light preload, at the cost of more heat generated at speed. A 25° bearing at medium preload suits a spindle doing heavier work at moderate speed — boring, heavy milling, grinding with real infeed.

The textile laminate cage is the speed-friendly counterweight. At roughly a fifth the density of brass it loads itself far less under centrifugal force, and the laminate holds a small oil reserve that helps the bearing survive a brief lubrication interruption.

Quantity and configuration

The UM suffix denotes a universally ground single bearing, and one bearing is what ships. Universal grinding is what makes that useful: two or more of these can be clamped into a back-to-back (DB) set for maximum moment stiffness and two-direction thrust, a face-to-face (DF) set where housing alignment is imperfect, a tandem (DT) set to double one-direction thrust, or a triplex stack — each combination developing the specified medium preload automatically.

Interchange guidance

Same-envelope 25° super precision equivalents include NSK 7026A5, SKF 7026 ACD/P4A, NTN 7026, RHP 7026-E-T-SUM-P4 and Fafnir/Timken 3MM9126WI, where the Fafnir 3MM prefix is 25°. Within FAG, B7026-C-TPA-P4-UM is the 15° version of the same envelope; it shares the 130 x 200 x 33 mm dimensions but not the contact angle, so it is carried here as a dimensional cross-reference rather than a direct substitute. Fafnir 2MM9126WI is likewise the 15° equivalent. A cross-reference matches on contact angle, cage code and preload class as well as base number.