21317 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 21317 model number is decoded

In SKF catalogue PUB BU/P1 17000, 21317 appears as 21317 E: an open, double-row spherical roller bearing, self-aligning by virtue of the sphered outer raceway, sized 85×180×41 mm to the ISO 15 boundary plan. On the SKF nameplate, 21317 follows the ISO 15 convention: 2 for the spherical roller type, 13 for the dimension series 13 (heavy OD, normal width), final digits 17 for the 85 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. The 47.5 mm radial section height ((180−85)/2) and 5200 g catalogue mass frame a 85 mm bore bearing rated at 331 kN C — roughly 3.89 kN of dynamic capacity per millimetre of bore before application factors. A 85 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

• Mount the 85 mm bore 21317 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 85 mm bore (180×41 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 41 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 21317; clearance reduction targets differ, and over-driving a cylindrical bore onto an oversized journal cracks the inner ring.
• The 331/375 kN ratings are SKF catalogue values for this exact execution (21317 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 21317 (cylindrical bore as listed, tapered-bore 21317 EK variant, plus sealed and vibrating-screen options in the same envelope); they are not interchangeable order numbers — quote the full 21317 E designation when purchasing.