21310 bearing: complete specifications & equivalents

Specification table

Source: catalog reference (SKF PUB BU/P1 17000/1 EN (Oct 2018), ch. 9.1 spherical roller bearings) · extracted 2026-09-26

Parameters extracted from the official SKF Rolling Bearings catalogue (SKF PUB BU/P1 17000/1 EN (Oct 2018), ch. 9.1 spherical roller bearings); SKF® and SKF Explorer® are trademarks of AB SKF, used here for identification only — mpnbase is not an authorized SKF distributor. Boundary dimensions are ISO 15 interchangeable; current production values may differ, verify at skf.com.

Cross references & equivalents

Interchange levels: full standard interchange · partial verify parameters · verify manual confirmation required. Links resolve to the equivalent model's specification page where available.

How the 21310 model number is decoded

In SKF catalogue PUB BU/P1 17000, 21310 appears as 21310 E: an open, double-row spherical roller bearing, self-aligning by virtue of the sphered outer raceway, sized 50×110×27 mm to the ISO 15 boundary plan. Digit by digit, 21310 reads as bearing type 2 (spherical roller, two barrel-roller rows), dimension series 13, and bore reference 10 resolving to 50 mm; 110 mm OD and 27 mm width are the matching ISO 15 boundary values. The trailing E is the SKF optimized internal design: larger rollers and a stamped window-type steel cage give higher load ratings than the older CC geometry; EK is the same bearing with a 1:12 tapered bore for adapter sleeves. The 30.0 mm radial section height ((110−50)/2) and 1350 g catalogue mass frame a 50 mm bore bearing rated at 159 kN C — roughly 3.18 kN of dynamic capacity per millimetre of bore before application factors. A 50 mm rotating inner ring usually runs k5 on the shaft with H7 in the housing; for vibrating-screen duty the outer ring is instead held tight and the shaft seat loosened — follow the screen builder's fit schedule.

Typical equipment & failure modes

Selection pitfalls — read before you substitute

• On this 50 mm bore, an interference inner-ring fit consumes a large share of the CN clearance; specify C3 when the inner ring rotates hot, and verify residual clearance after mounting rather than trusting the catalogue clearance class.
• The 21300-series series at 50 mm bore (110×27 mm) pairs a heavy OD with a narrow section — a compact way to add capacity, but the shoulder and abutment diameters differ from the 222 series; it is not a drop-in swap.
• Shaft and housing fillets must clear the bearing chamfer so the 27 mm-wide rings seat square; use an undercut or withdrawal groove rather than an oversized radius that locks on the ring face.
• Never use the tapered-bore EK/K variant's drive-up figures on this cylindrical-bore 21310; clearance reduction targets differ, and over-driving a cylindrical bore onto an oversized journal cracks the inner ring.
• The 159/166 kN ratings are SKF catalogue values for this exact execution (21310 E); SKF can revise internal geometry without changing the order number, so keep the catalogue version (SKF catalogue PUB BU/P1 17000) with the specification and re-verify for critical drives.
• SKF lists several executions of 21310 (cylindrical bore as listed, tapered-bore 21310 EK variant, plus sealed and vibrating-screen options in the same envelope); they are not interchangeable order numbers — quote the full 21310 E designation when purchasing.