21317-EK bearing: complete specifications & equivalents

Specification table

Source: catalog reference (SKF PUB BU/P1 17000/1 EN (Oct 2018), ch. 9.2 adapter-sleeve executions) · extracted 2026-09-26

Parameters extracted from the official SKF Rolling Bearings catalogue (SKF PUB BU/P1 17000/1 EN (Oct 2018), ch. 9.2 adapter-sleeve executions); 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-EK model number is decoded

In SKF catalogue PUB BU/P1 17000, 21317-ek denotes the tapered-bore version (K suffix, taper 1:12) of the 21300-series spherical roller bearing: dimensioned 85×180×41 mm, it seats on an adapter or withdrawal sleeve rather than directly on a machined journal. On the SKF nameplate, 21317-ek 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. Reading the suffix on 21317-ek, the K (or EK/CCK) element changes only the bore — 1:12 taper for sleeve mounting — while the rest of the suffix chain (CC cages with W33 groove) keeps the same internal design, cage and W33 relubrication features as the cylindrical-bore 21317. With C 331 kN and C0 375 kN, the 21317-ek 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. After drive-up, re-check radial clearance and then swing the outer ring through its self-aligning range: the sphered raceway of the 21317-ek must still tilt ≈ 0.5–2.5° freely — a joint that binds after sleeve mounting signals excessive drive-up or a cocked sleeve.

Typical equipment & failure modes

Selection pitfalls — read before you substitute

• Mount the 85 mm bore 21317-ek 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.
• Never apply the drive-up or clearance-reduction figures for this 1:12 tapered 21317-ek to a bearing of the other taper (1:12 vs 1:30); the steeper taper moves far less clearance per nut turn and the targets come from different catalogue tables.
• Never apply the drive-up or clearance-reduction figures for this 1:12 tapered 21317-ek to a bearing of the other taper (1:12 vs 1:30); the steeper taper moves far less clearance per nut turn and the targets come from different catalogue tables.
• Catalogue reference speed and limiting speed are different limits: the 3,800 r/min reference is a thermal criterion under load, while the 5,300 r/min limiting value is the mechanical ceiling — observe both.
• The 331/375 kN ratings are SKF catalogue values for this tapered-bore execution (SKF 21317 EK); sleeve, KM nut and MB washer are separate order numbers, and the catalogue version (SKF catalogue PUB BU/P1 17000) should travel with the mounting specification.