QJ-315-N2PHAS 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-315-N2PHAS model number is decoded

QJ 315 N2PHAS is SKF's 75 mm-bore QJ four-point contact ball bearing of the QJ300 series, 75×160×37 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. N2 marks two locating slots, 180° apart, in one outer-ring side face: pins or dogs engage the slots to stop the outer ring turning in its radially-clear housing bore. glass-fibre reinforced PEEK cage, outer-ring-centred with lubrication grooves in the guiding surfaces (suffix PHAS), for very high-speed oil-air or grease lubrication. Envelope 75×160×37 mm (2.953×6.299×1.457 in), 42.5 mm radial section height, C 216 kN, C0 200 kN, Pu 7.8 kN.SKF publishes only the 7,500 r/min limiting speed for this execution, catalogue mass 3900 g. Envelope economics: the 37 mm width over a 42.5 mm section yields 0.87 mm of ring width per section millimetre, and the bearing weighs 3900 g for 216 kN of dynamic capacity — about 18 g per rated kN. Mass and section check: 3900 g inside the 75×160×37 mm outline leaves a 42.5 mm radial section, and the 200 kN static rating is 0.93× the dynamic rating — plan static safety and minimum load against those numbers rather than against sister executions. Speed-ratio note for this exact unit: no thermal reference speed is listed (seal/grease life governs), so the 7,500 r/min limiting value is the single published ceiling. Locating-slot execution: the two N2 notches are milled into one outer-ring side face exactly 180 degrees apart and engaged by housing dogs or headed pins during assembly; verify dog engagement by hand before the cover goes on, deburr the slot edges after any housing rework, and re-inspect the slot roots for fretting marks at each overhaul because a dog that rides only one slot lets the outer ring walk. The slots identify this order number unmistakably: the plain MA/PHAS execution of the same bore has no notches and must be secured differently.

Typical equipment & failure modes

Selection pitfalls — read before you substitute

• Apply the Fa/Fr ≥ 1,27 condition: at lower ratios the balls contact both sides of a raceway, increasing friction and shortening life — the paired radial bearing should carry the radial share.
• 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.
• 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 built into QJ-315-N2PHAS: check the two N2 slot faces and the engaging housing dogs at every refit, and never rely on cover friction to stop the radially loose outer ring.
• The PHAS PEEK cage of QJ-315-N2PHAS is outer-ring-centred with lubrication grooves: feed clean oil-air or appropriate grease to the guide land and inspect groove filling at overhaul.
• Catalogue ratings are SKF PUB BU/P1 17000 figures for QJ 315 N2PHAS as the qj slotted execution; the other order numbers of the QJ 315 size are different products and may carry different ratings — always quote the full designation when purchasing.