21320 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 21320 model number is decoded

SKF 21320 (21320 E) is the spherical-roller choice for a 100 mm shaft — barrel rollers between an inner ring with two raceways and a common sphered outer raceway inside the 215×47 mm ISO 15 envelope. On the SKF nameplate, 21320 follows the ISO 15 convention: 2 for the spherical roller type, 13 for the dimension series 13 (heavy OD, normal width), final digits 20 for the 100 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. With C 433 kN and C0 490 kN, the 21320 load check covers radial plus moderate axial in either direction — but below the minimum load the rollers skid, so verify P ≥ 0.01·C0 at the lightest operating point. Drive-on force must go through the ring being fitted: press or induction-heat the inner ring onto the 100 mm shaft (max 120 °C) and never transmit mounting force through the roller complement, or the raceways brinell.

Typical equipment & failure modes

Selection pitfalls — read before you substitute

• Mount the 100 mm bore 21320 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 100 mm bore (215×47 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 21320; clearance reduction targets differ, and over-driving a cylindrical bore onto an oversized journal cracks the inner ring.
• The self-aligning feature is not a license to ignore alignment: beyond ≈ 0.5–2.5° (series-dependent) the edge loading eats the fatigue margin, and seal drag grows as the rings tilt.
• The 433/490 kN ratings are SKF catalogue values for this exact execution (21320 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 21320 (cylindrical bore as listed, tapered-bore 21320 EK variant, plus sealed and vibrating-screen options in the same envelope); they are not interchangeable order numbers — quote the full 21320 E designation when purchasing.