7318 bearing: complete specifications & equivalents

Specification table

Source: catalog reference (SKF PUB BU/P1 17000/1 EN (Oct 2018), ch. 3.1 single-row ACBB) · extracted 2026-09-26

Parameters extracted from the official SKF Rolling Bearings catalogue (SKF PUB BU/P1 17000/1 EN (Oct 2018), ch. 3.1 single-row ACBB); 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 7318 model number is decoded

7318 BEP belongs to SKF's universal single-row angular-contact range — the 90 mm bore entry in the medium (7300) series, dimensioned 190 mm OD and 43 mm wide to the same ISO 15 boundary plan as the 6318 deep-groove envelope.Reading the designation: the leading 7 marks a single-row angular-contact ball bearing, the 3 is ISO diameter series 3 (medium section), and the last two digits encode the 90 mm bore; the 190 mm OD and 43 mm width follow the ISO 15 general plan. Suffix letters after 7318 describe the build: B fixes the 40° contact angle, E denotes the reinforced internal geometry, and P identifies the moulded PA66 glass-fibre cage rather than a stamped-steel or machined-brass one. At 4,300 r/min reference speed the 50.0 mm-section 7318 is governed thermally by preload and lubricant flow; oil-air or grease pack selection should be made against that value, with 4,000 r/min as the mechanical ceiling. A single 7318 locates the shaft in one axial direction only; for bidirectional location order a matched pair — DB for moment stiffness, DF for tolerance of thermal expansion — and size the preload against the real load and speed of the position.

Typical equipment & failure modes

Selection pitfalls — read before you substitute

• Mount the 90 mm bore 7318 by induction heating of the inner ring (max 120 °C — the PA66 cage sets the ceiling, not the steel); driving it home through the outer ring or balls brinells the asymmetric raceway.
• The 73xx medium section at 90 mm bore (190×43 mm) is heavier-rated than the 7218 but runs hotter at the same speed; do not substitute a 7318 into a 72-series spindle position without re-checking dn, lubricant film and preload.
• When the outer ring rotates, reverse the fit logic and provide outer-ring location; the steep 40° contact of 7318 pushes the rings apart under load, so a non-located outer ring walks its seat even when the shaft is fixed.
• DB (back-to-back) pairs are stiffer against moments, DF (face-to-face) pairs tolerate misalignment and thermal growth better; choosing the arrangement from the 2D drawing rather than the actual shaft thermal expansion is a common 7318 mounting error.
• Catalogue reference speed and limiting speed are different limits: the 4,300 r/min reference is a thermal criterion under load, while the 4,000 r/min limiting value is the mechanical ceiling — observe both.
• The 156/134 kN ratings are SKF catalogue 17000 values for the 7318 BEP execution; SKF can revise internal geometry without changing the order number, so keep the catalogue version (PUB BU/P1 17000/1 EN, 2018) with the specification and re-verify for critical drives.
• SKF lists several executions of 7318 (BEP basic, BECBP universally matchable, BE-2RZP sealed, BECBM brass-cage, ACC-series at 25°); they are not interchangeable order numbers — quote the full 7318 BEP designation when purchasing and match the execution to the mounting arrangement.
• A plain 7318 BEP is a single open bearing, not a universally matchable one; to mount a defined DB/DF pair order the BECBP (CB) execution — pairing two unmatched basic units gives uncontrolled preload because the side faces are not ground for set mounting.