Timken7316WNSUAngular Contact Ball Bearing 80 x 170 x 39 mm, 40° Contact Angle, Universally Flush Ground Single, Metal Cage, Open

Product Description

What this part is

A Timken (Fafnir) 7316WN SU single-row angular contact ball bearing, 80 mm bore × 170 mm outside diameter × 39 mm wide, with a 40° contact angle and a metal cage. It is a medium-series industrial bearing built for heavy thrust in one direction, and it is universally flush ground — so two of them butt together into a back-to-back, face-to-face or tandem pair with no shims and no measured spacer. Made in USA.

Decoding the designation

7300 — ISO medium series, single-row angular contact. Bore code 16 = 80 mm (16 × 5).
WN — Timken’s construction code for an angular contact bearing counterbored with a low shoulder on both the inner and outer rings. Timken’s own nomenclature chart assigns 40° to WN.
SU — flush ground on both faces for universal mounting, supplied as a single bearing to a controlled clearance. DU is the factory-matched pair.

Why there is no preload letter, and why nothing is missing:
Buyers who know the super precision line often ask whether this part number is incomplete — shouldn’t SU carry an L, M or H for light, medium or heavy preload? No. The lettered forms SUL, SUM, SUH and SUX belong to Timken’s super precision range (the MM, MMV and MMX grades, ABEC 7 and above), where SU denotes a preload level. On the standard industrial 7000W and 7000WN line there are exactly three options — SU, DU or no suffix — and here SU denotes a controlled clearance, not a preload. So 7316WN SU is a complete and correct designation: a universally flush ground single, ground so it can be duplex mounted without shimming. No preload letter applies, and none is missing.

What these specs mean in practice

40° is the heavy-thrust end of the angular contact range. Compared with a 15° or 25° bearing of the same envelope it carries far more axial load and is much stiffer axially, but it is speed-limited and it is fussier about thrust always acting in the intended direction. That is the trade you are buying: this bearing is for a shaft with a large, steady, one-way thrust load — a vertical drive, a heavily loaded worm or bevel gearbox, a press or extruder screw — not for a lightly loaded high-speed spindle. The low shoulder on both rings (the WN counterbore) is what lets the extra ball complement in and what gives the bearing its high rating; it also means the assembly is directional and cannot take reversing thrust of any magnitude. Universal flush grinding is the practical convenience: because both faces are ground to a controlled height, you can stack a second SU against this one and get a predictable clearance rather than having to measure and shim on the bench.

Published ratings and mounting data

From Timken (cad.timken.com, 7316WN SU record)

Basic dynamic radial load rating C — 153,000 N (34,500 lbf)
Basic static radial load rating C0 — 108,000 N (24,500 lbf)
Contact angle — 40°
Limiting speed — 2,800 rpm grease, 3,200 rpm oil
Bearing weight — 4.504 kg (9.92 lb)
Shaft backing shoulder diameter — 91.90 mm (3.620 in)
Housing backing shoulder diameter — 158.0 mm (6.220 in)
Maximum shaft fillet radius — 2.000 mm (0.083 in)
Closure — open, no shield or seal

Do not substitute the modern 7316 B figures for these. Timken also sells a 7316 B at exactly this envelope, and it is a different bearing: 134.80 kN dynamic, 109.20 kN static, 3,800 rpm grease / 5,100 rpm oil, 3.72 kg. The WN SU is the stronger and slower of the two. Mixing the two datasheets is an easy and expensive mistake.

Two cells are left blank. Precision class is not published per part; Timken states only at series level that “the 7000WN bearings are manufactured with better than ABEC 1 inner ring bore tolerances and ABEC 3 running accuracy,” which is what this page reports rather than inventing a class. Ball complement is not published.

Quantity and configuration

One bearing, in its original sealed factory wrapper. SU means it is a single, ground so it can be paired — it is not itself a pair. If your application calls for a duplex mount, you need two, and buying two SU singles from the same size and grade is the intended way to do it, since universal grinding is exactly what makes that work without shims.

Fitting notes

The outer ring is etched FAFNIR®, 7316WN SU, USA, THRUST and LOT #2208327. The THRUST face must go toward the load. On a 40° bearing this matters more than on any other angle, because essentially all of the bearing’s advantage is directional — fitted backwards it is both weaker and shorter-lived than the cheap deep groove bearing it replaced. The cage is a gold-coloured metal cage, visible in the photographs and consistent with Timken’s published one-piece ball-piloted pressed brass construction; machined bronze (MBR) is a documented option in the WN range, so if the cage material is critical to your specification, ask us to confirm it against the ring before you order. Observe the backing shoulder diameters and the 2 mm maximum fillet radius, and provide an opposed axial location for the shaft.

Interchange guidance

The 80 × 170 × 39 mm, 40° combination is the ISO 7316 envelope, and Timken’s angular contact catalogue confirms 7316 at exactly these dimensions with a 40° angle for the 7200 and 7300 series. So other makers’ 40° 7316 B-type bearings share both the envelope and the angle and will physically fit. Timken publishes no brand-to-brand interchange table for this part, so no specific competitor number is asserted here — and note the caution above that even Timken’s own 7316 B has materially different ratings and speeds. Fafnir is a retired brand name absorbed into Timken; a current-production order goes in as a Timken 7316WN SU.