21312 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 21312 model number is decoded

For a 60 mm shaft carrying heavy radial load with misalignment or deflection, SKF lists 21312 under catalogue execution 21312 E: two barrel-roller rows on a sphered outer raceway. On the SKF nameplate, 21312 follows the ISO 15 convention: 2 for the spherical roller type, 13 for the dimension series 13 (heavy OD, normal width), final digits 12 for the 60 mm bore. 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. At 4,800 r/min reference speed the 35.0 mm-section 21312 is governed thermally by lubricant flow through the W33 groove and the two-row roller complement; grease or oil selection should be made against that value, with 6,300 r/min as the mechanical ceiling. The cylindrical-bore execution here seats directly on the shaft journal; if the application calls for an adapter sleeve, order the tapered-bore 21312 EK variant instead and measure the drive-up or clearance reduction, not the nut torque.

Typical equipment & failure modes

Selection pitfalls — read before you substitute

• Mount the 60 mm bore 21312 by induction heating (max 120 °C) or oil injection — driving a bearing of this section home through the rollers brinells both raceways, and the damage only speaks up as vibration hours later.
• The 21300-series series at 60 mm bore (130×31 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.
• Never use the tapered-bore EK/K variant's drive-up figures on this cylindrical-bore 21312; clearance reduction targets differ, and over-driving a cylindrical bore onto an oversized journal cracks the inner ring.
• Catalogue reference speed and limiting speed are different limits: the 4,800 r/min reference is a thermal criterion under load, while the 6,300 r/min limiting value is the mechanical ceiling — observe both.
• The 217/240 kN ratings are SKF catalogue values for this exact execution (21312 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 21312 (cylindrical bore as listed, tapered-bore 21312 EK variant, plus sealed and vibrating-screen options in the same envelope); they are not interchangeable order numbers — quote the full 21312 E designation when purchasing.