Fafnir7204WAngular Contact Ball Bearing 20 x 47 x 14 mm, Maximum Capacity Filling Slot, Pressed Brass Cage, Open, Unground Single

Product Description

What this part is

A Fafnir (now Timken) 7204W single-row angular contact ball bearing, 20 mm bore × 47 mm outside diameter × 14 mm wide, with a one-piece pressed brass cage. It carries radial load together with thrust in one direction. Unlike the super precision spindle bearings that share the 7200 number block, this is Timken’s standard industrial-grade angular contact bearing — an unground, non-matched single. Made in USA.

Decoding the designation

7200 — ISO light series, single-row angular contact. Bore code 04 = 20 mm (4 × 5).
W — Timken’s construction code for an angular contact bearing with a low shoulder on the outer ring only, of maximum-capacity filling-slot design. The filling slot lets more balls into the raceway than a Conrad assembly allows, which is where the extra load rating comes from.
No trailing suffix — per Timken’s own Fafnir lettering system, a bare 7204W is an unground, single-packaged bearing. It is not universally flush ground and not preload-matched. The flush-ground version is 7204W SU; a factory-matched light-preload pair is 7204W DU.
C1 on the ring — a Timken manufacturing code, not a clearance class. Do not read it as ISO C1 internal clearance.

Correcting the source data

The previous description listed “7204 B Y G / 7204 BEG/AP/AY/BG / 7204 BEA / 7204 BEC” as equivalents. Those have been removed. Three reasons. They are garbled renderings of SKF and FAG designations rather than clean part numbers; the SKF 7204 B family is a 40° non-filling-slot bearing, which is a different construction from a maximum-capacity filling-slot W; and Timken publishes no brand interchange for Fafnir angular contact at all, so presenting them as equivalents was unsupported. What is defensible is the dimensional envelope, and that is what this page now states.

Contact angle — why this page does not state one:
We would rather leave a cell empty than fill it with a number we cannot stand behind. Timken’s own sources contradict each other on the contact angle of the 7204W. The authoritative Fafnir lettering system (order 5730) defines suffix W as “20 and 30 degree contact angle (depending on size)” and cites 7204W as its worked example. Timken’s current CAD portal instead states 40° on the 7204W page — but that text is a family-level boilerplate block, byte-identical to the block on the 7316WN page, including a line about 200-series interchange that is plainly wrong for an 80 mm bearing. Distributors who resell Timken’s data feed repeat the 40° figure, so they are not independent confirmation. The honest position: the angle is somewhere in the 20–40° range and Timken has published two incompatible answers. If the exact angle governs your calculation, ask us and we will put the question to Timken applications engineering before you commit.

What these specs mean in practice

A single-row angular contact bearing takes thrust in one direction only, so it needs an opposing bearing or a shoulder to locate the shaft the other way. The maximum-capacity filling-slot design is the trade-off worth understanding: packing extra balls in lifts the load rating well above a Conrad-assembly bearing of the same envelope — the published dynamic rating here is 16,800 N against roughly 13,300 N for a modern ISO 7204 B at the same size — but the filling slot interrupts the raceway shoulder, so the bearing is less tolerant of misalignment and of thrust reversal than a non-slotted design. The pressed brass cage is ball-piloted and one-piece, which keeps it quiet and tolerant of marginal lubrication.

Published ratings and mounting data

From Timken (cad.timken.com, 7204W record)

Basic dynamic radial load rating C — 16,800 N (3,800 lbf)
Basic static radial load rating C0 — 8,100 N (1,830 lbf)
Bearing weight — 0.104 kg (0.230 lb)
Shaft backing shoulder diameter — 29.920 mm
Housing backing shoulder diameter — 37.470 mm
Maximum shaft fillet radius — 1 mm (0.039 in)
Cage — one-piece, ball-piloted, pressed brass
Closure — open, no shield or seal

Two figures are deliberately absent. Limiting speed is not published by Timken for the 7204W — the CAD record carries a speed for other parts in this family but not this one, so the omission is real rather than an oversight on our side. Precision class is not published per part either; Timken’s series-level statement covers only the WN bearings (“better than ABEC 1 inner ring bore tolerances and ABEC 3 running accuracy”), and distributor listings quoting ABEC 1 / ISO P0 for the 7204W are secondary sources. Ball complement is not published.

Quantity and configuration

Priced and sold individually. Two are in stock, in original red Fafnir cartons with their factory wrapping intact. Because a bare 7204W is unground and not preload-matched, two of them are not a duplex set: mounting two adjacent requires measured shims or a ground spacer to set the clearance, and even then the result is not equivalent to a factory-matched 7204W DU pair. If you need a matched pair, order the DU version.

Fitting notes

The outer ring is etched THRUST on one face, alongside FAFNIR® 7204W C1 USA and a factory lot number. That marked face must go toward the thrust load — installed backwards, the low outer-ring shoulder faces the load and the bearing cannot carry the thrust it was chosen for. This is the single most common way an angular contact bearing gets ruined on the bench. Respect the backing shoulder diameters and the 1 mm maximum fillet radius above so the rings seat square, and remember the bearing needs an opposed location to fix the shaft axially in the other direction.

Interchange guidance

The 20 × 47 × 14 mm envelope is ISO 7204. That much is a genuine dimensional equivalence and any 7204-series angular contact bearing will physically fit the same shaft and housing. Beyond the envelope, be careful: contact angle and construction vary widely across that number — SKF 7204 B and 7204 BE are 40°, 7204 AC is 25°, and none of them is a maximum-capacity filling-slot design. Given that the 7204W’s own angle is unresolved (see above), we are not asserting any brand-to-brand interchange, and Timken publishes none. Fafnir is a retired brand name absorbed into Timken, so a current-production order goes in as a Timken 7204W — add SU if you need it flush ground for adjacent mounting.