Spherical Roller Bearing Size Chart: Dimensions, Load Ratings, and Speed Limits by Series

A spherical roller bearing (SRB) is identified first by its series — 213, 222, 223, 230, 231, 232, 238, 239, 240, 241, 248, or 249 — and then by a two-digit size code. The series number tells you the cross-section and load capacity; the size code tells you the bore. Get either one wrong when specifying a replacement and the bearing simply won't fit the housing or the shaft.

This chart covers the two series that account for most industrial replacements: the 222 series (single-width, for general machinery) and the 223 series (wider, higher radial capacity, common in vibrating screens and gearboxes). Bore sizes run from 30 mm to 200 mm, which covers the range used in pumps, gearboxes, conveyor pulleys, and fans.

Dimensions follow ISO 15312, so the values below apply across manufacturers for a given series and size code; load ratings are given for the cylindrical-bore, flangeless-inner-ring design as a baseline.

How to Read a Spherical Roller Bearing Designation

A designation like 22315 EK breaks down as:

• 223 – series (design/width class)

• 15 – size code; multiply by 5 to get the bore in mm (15 × 5 = 75 mm)

• E – the higher-capacity "E-design" with a flangeless inner ring and reinforced roller set

• K – tapered bore (1:12 taper); no letter means cylindrical bore

Suffixes like C3 or C4 indicate a radial clearance class greater than Normal — that's covered in the mounting and clearance guide, not here.

222 Series — Standard Width

223 Series — Wide Width, Higher Radial Capacity

The 223 series is a separate, wider design line from the 222 series — not just a bigger version of it. At the same bore, 223-series width runs roughly 45–60% greater than 222-series width, which typically pushes the dynamic load rating up by 70% to more than double. It's the go-to option when a housing already has the axial room and the application is radial-load-dominant — vibrating screens, crushers, and slow-speed gearboxes.

Two Numbers That Matter More Than People Think

Dynamic load rating (Cr) is the load a bearing can theoretically carry for 1 million revolutions at 90% survival probability — it's a fatigue-life number, not a break point. Static load rating (C0r) is the load that produces a permissible permanent deformation at the contact points; this is the number that matters for a bearing that sits still under load most of the time, like a mill roll parked overnight under its own weight.

A common sizing mistake: picking a bearing by bore diameter alone and assuming any bearing in that bore size will do. At a 100 mm bore, the 222-series 22220 carries a 433 kN dynamic load rating; the 223-series 22320, at the same bore, carries 847 kN — nearly double. If the application's actual radial load is unclear, that gap is exactly where an undersized bearing gets ordered.

Reference Speed vs. Limiting Speed: The Number That Actually Caps Your Application

Catalog speed ratings for a spherical roller bearing come in two flavors, and mixing them up leads to over-speeding a bearing without realizing it. Reference speed is a thermal rating — the rotational speed at which heat generation and heat dissipation reach equilibrium under standardized test conditions (ISO 15312). Limiting speed is a mechanical rating — the ceiling set by cage strength, lubricant retention, and roller dynamics, and it's typically higher than the reference speed.

For a 22220 (100 mm bore), the reference speed is 3,400 rpm while the limiting speed is 4,500 rpm — a 32% gap. The limiting speed is the number stamped on most supplier data sheets, and it's tempting to treat it as "the" speed rating.

But an application running consistently near the limiting speed, especially with grease lubrication or elevated ambient temperature, is running with far less thermal margin than the number suggests. When speed, load, and temperature are all pushing toward the upper end of a bearing's rating simultaneously, sizing against the reference speed rather than the limiting speed is the more conservative — and usually correct — choice.

FAQ

Does a larger outer diameter always mean a higher load rating?

Not necessarily. Width matters as much as OD. A 223-series bearing can have a smaller OD than the next size up in the 222 series but still carry a higher dynamic load, because the extra width adds roller length rather than roller diameter.

Can a 222-series bearing be swapped for a 223-series bearing at the same bore?

Only if the housing has enough axial clearance — the 223 series runs roughly 45–60% wider at most bore sizes, and the OD is typically 15–20% larger too. Check both dimensions against the housing bore and shoulder width before ordering a swap.

Where do tapered-bore (K) dimensions differ from cylindrical-bore ones?

Bore and OD are identical; only the bore profile changes. Mass drops slightly (a few percent) because the tapered bore removes a small amount of material from the inner ring — negligible for sizing purposes.

Boundary dimensions shown conform to ISO 15312. Load ratings and speeds shown are for the E-design/optimized-internal-geometry variant and have been cross-checked against currently listed part numbers; older or heavy-duty design variants of the same designation (different cage or roller geometry) can carry meaningfully different ratings at an identical bore and OD. Confirm the exact figures for your specific part number before finalizing a design.