QJ-313-MA bearing: complete specifications & equivalents

Specification table

Source: catalog reference (SKF PUB BU/P1 17000/1 EN (Oct 2018)) · extracted 2026-09-27

Parameters extracted from the official SKF Rolling Bearings catalogue (SKF PUB BU/P1 17000/1 EN (Oct 2018)); 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 QJ-313-MA model number is decoded

QJ 313 MA is SKF's 65 mm-bore QJ four-point contact ball bearing of the QJ300 series, 65×140×33 mm, with a two-piece inner ring for bidirectional axial location beside a radial bearing. QJ identifies a four-point contact ball bearing with a two-piece inner ring: the gothic-arch raceways seat each ball at four points, giving axial location in both directions while a paired radial bearing carries the radial load. machined brass cage, outer-ring-centred (suffix MA), which guides on the outer ring rather than on the balls. Envelope 65×140×33 mm (2.559×5.512×1.299 in), 37.5 mm radial section height, C 176 kN, C0 156 kN, Pu 6.55 kN.SKF publishes only the 8,500 r/min limiting speed for this execution, catalogue mass 2700 g. The 6.55 kN fatigue load limit is the equivalent-load floor for long-life adjustment; with 176/156 kN ratings and 2700 g mass this execution carries about 2.71 kN of C per millimetre of bore. Sizing arithmetic on the 65 mm bore: 176 kN C divided by the 37.5 mm radial section height gives 4.7 kN per section millimetre; the 2700 g mass and 4 % Pu/C share frame the light-load floor for the adjusted-life check. Bore-to-OD planning: OD 140 over bore 65 is a 2.15× step for this size, and the 33 mm width gives a bore/width ratio of 1.97; use these ratios when housing space around the 65 mm shaft is the first constraint. Plain outer-ring execution: this order number is delivered without N2 locating slots, so anti-rotation is solved in the housing instead — a shoulder dog, a spring-loaded key, a cover feature or an interference-free circlip arrangement. Because the outer ring deliberately runs with radial clearance and a small axial float gap, omitting positive anti-rotation invites seat fretting; the slotted N2 order number is the alternative when the housing can provide engagement pins.

Typical equipment & failure modes

Selection pitfalls — read before you substitute

• Run the QJ as a thrust bearing with radial clearance in the housing, paired with a separate radial bearing; the QJ outer ring must not be radially clamped.
• Without N2 slots, provide another positive anti-rotation feature for the radially loose outer ring
• Run the QJ as a thrust bearing with radial clearance in the housing, paired with a separate radial bearing; the QJ outer ring must not be radially clamped.
• Anti-rotation is NOT built into QJ-313-MA: without N2 slots the housing must provide a dog, keyed cover or other positive stop, since the outer ring runs radially loose by design.
• The MA brass cage of QJ-313-MA is outer-ring-centred: its guide land needs an uninterrupted oil film, so check lubricant reach when the bearing is used purely as a thrust location.
• Catalogue ratings are SKF PUB BU/P1 17000 figures for QJ 313 MA as the qj plain execution; the other order numbers of the QJ 313 size are different products and may carry different ratings — always quote the full designation when purchasing.