7304 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 7304 model number is decoded

7304 BEP belongs to SKF's universal single-row angular-contact range — the 20 mm bore entry in the medium (7300) series, dimensioned 52 mm OD and 15 mm wide to the same ISO 15 boundary plan as the 6304 deep-groove envelope.The code breaks down as type prefix 7 (angular contact), diameter series 3 (the medium section), and bore code 04 = 20 mm; dimensions 20×52×15 mm therefore match the 6304 deep-groove envelope even though the internal design is different. In SKF suffix language B sets the steep 40° angle for high axial capacity, E is the optimised internal design, and P is the polymer cage; variants with seals (BE-2RZP), 25° angles (A/ACC) or brass cages (BECBM) are separate order numbers. Catalogue mass 140 g for the 20×52×15 mm open execution covers the PA66 cage and standard ball complement; sealed or brass-cage variants of the same size differ slightly in mass and carry their own order numbers. For a 20 mm shaft the usual seat is k5 with an H7 housing when the inner ring rotates; arrange two 7304 bearings as a set for two-direction location and set preload from the load diagram, never from assembly feel.

Typical equipment & failure modes

Selection pitfalls — read before you substitute

• At a 20 mm bore the thin rings are easily distorted by an over-tight shaft nut; check seat runout (target Ra ≤ 0.8 µm) and torque the locknut progressively — a pinched 7304 shows up as spindle vibration long before it fails.
• The 73xx medium section at 20 mm bore (52×15 mm) is heavier-rated than the 7204 but runs hotter at the same speed; do not substitute a 7304 into a 72-series spindle position without re-checking dn, lubricant film and preload.
• Do not mix execution classes inside one 7304 pair — universal-matchable (CB) bearings are ground for arbitrary pairing, but a CB unit paired with an unmatched basic BEP bearing will not share preload evenly.
• Preload is a design value, not an assembly feel: excessive preload in the 7304 pair raises operating temperature and can trigger thermal runaway back-to-back, while too little lets the balls skid and smear the raceway under light load.
• Open 7304 units need application-supplied sealing and a defined lubricant supply; in oil lubrication keep the oil level below the lowest rolling element or churning raises temperature well beyond the catalogue speed figures.
• The 17.4/9.5 kN ratings are SKF catalogue 17000 values for the 7304 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 7304 (BEP basic, BECBP universally matchable, BE-2RZP sealed, BECBM brass-cage, ACC-series at 25°); they are not interchangeable order numbers — quote the full 7304 BEP designation when purchasing and match the execution to the mounting arrangement.
• A plain 7304 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.