FAGB7032CTP4SULSuper Precision Angular Contact Ball Bearing 160 x 240 x 38 mm, 15° Contact Angle, P4S Tolerance, Phenolic Cage, Universal Light Preload

Product Description

What this part is

A super precision angular contact ball bearing in the 7032 envelope — 160 mm bore, 240 mm outside diameter, 38 mm width. Single row, open, universally ground, at the tolerance grade machine tool builders specify for main spindle positions. At 160 mm bore this is a large-machine bearing: heavy milling heads, large grinders, boring mills and turning centre spindles.

Decoding the designation

B — FAG spindle bearing series, a higher-precision execution than a standard 70-series angular contact bearing.
7032 — ISO boundary dimensions, 160 x 240 x 38 mm.
C — 15° contact angle in FAG nomenclature.
T — phenolic (textile laminate) cage.
P4S — super precision tolerance, ABEC 7 running accuracy with tighter bore and outside diameter control and matched widths for universal grinding.
UL — universal grinding, light preload, supplied as a single bearing. The SUL form seen on some paperwork carries the same meaning: single, universally ground, light preload.

What these specs mean in practice

Contact angle is the first thing to check on a spindle bearing and 15° is the speed-biased end of the range. The shallow angle limits how far the ball rides up the raceway shoulder, so ball spin, friction and heat generation stay low and permissible rpm is higher than the 25° (FAG suffix E) version of the same envelope. The trade is axial capacity and axial stiffness. At 160 mm bore this matters more than usual, because surface speed at the ball track and thermal growth in the spindle both scale with diameter — a large bearing has less thermal headroom to give away.

The phenolic cage follows the same logic: about a fifth the density of brass, so far less centrifugal stress on the cage at speed, and the laminate holds a small oil reserve through a lubrication interruption. It does not like sustained high temperature, so clean lubrication and light grease fills are part of the deal.

Light preload keeps friction and heat rise to a minimum. Medium (UM) and heavy (UH) executions of the same bearing buy stiffness and give up speed.

Quantity and configuration

One bearing ships. UL and SUL both denote a single universally ground bearing rather than a matched set — worth stating plainly, since a paired DUL designation looks similar on paper. Universal grinding means two of these clamped together develop the specified light preload with no shims, in back-to-back (DB), face-to-face (DF) or tandem (DT) orientation, and three can be stacked as a triplex. Order one to replace a failed half of an existing pair, or the matching count for a complete arrangement.

Fitting notes

At this bore size, thermal mounting is the sensible method — heat the inner ring evenly in an induction heater or oil bath to a controlled temperature and slide it onto the journal. Never press through the balls and never apply a torch. Shaft journal and housing bore need to be ground with runout and roundness held to a few microns and abutment faces square, or the bearing runs with a built-in error regardless of its own accuracy. When building a set, keep the marked faces oriented correctly; reversing a bearing changes the preload. Use a spindle grease or an oil mist or oil-air system sized for the bore and speed, and keep the fill light — a large preloaded bearing packed with grease will overheat well before rated speed.

Interchange guidance

Same-envelope 15° super precision equivalents include NSK 7032C, SKF 7032 CD/P4A, NTN 7032C and Fafnir/Timken 2MM9132WI, where the Fafnir 2MM prefix is 15° and so a true angle match. FAG B7032-E and Fafnir 3MM9132WI are the 25° versions of the same 160 x 240 x 38 mm envelope — dimensionally interchangeable but a different bearing in a preloaded stack, so they are carried as dimensional cross-references only.