BA-6 bearing: complete specifications & equivalents

Specification table

Source: catalog reference (SKF PUB BU/P1 17000/1 EN (Oct 2018)) · extracted 2026-09-28

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 BA-6 model number is decoded

For a 6 mm shaft, BA 6 is the BA miniature single-direction thrust ball bearing from SKF (bore spelled out in millimetres after BA): loose shaft washer, loose housing washer and a pressed steel ball-cage set, outline 6×14×5 mm. Three separable parts make the set: the tight-bore shaft washer that locates on the shaft, the loose-bore housing washer in its register, and the ball-cage assembly; load is purely axial and acts in one direction. BA is SKF's miniature designation: below 10 mm bore the usual two-digit code is dropped and the number after BA spells the shaft diameter in millimetres, making BA 6 a 6 mm bearing. at BA size the ball-cage assembly is a tiny stamped sheet-steel retainer delivered loose with the two washers — there is no riveted or polymer-cage variant at this scale. Envelope 6×14×5 mm (0.236×0.551×0.197 in), 4.0 mm radial section, C 1.78 kN, C0 1.92 kN, Pu 0.071 kN. reference speed 17,000 r/min (thermal) and limiting speed 24,000 r/min (mechanical), catalogue mass 4 g. Selection figures for BA 6: the C0/C ratio is 1.08, Pu 0.071 kN is about 4 % of C, and the catalogue mass works out to roughly 1 g per millimetre of bore; the printed minimum-load factor is A 1.90×10^-5. Load balance: C0 1.92 kN against C 1.78 kN gives a 1.08 ratio — thrust ball bearings are chosen on static rating and F_a/C0 far more often than on L10 life, while Pu 0.071 kN enters the adjusted-life check. Light-load floor: Pu = 0.071 kN is the equivalent-load threshold below which the SKF adjusted-life equation credits very long life for BA 6; the number is 4 % of the 1.78 kN dynamic rating. Preload at the mechanical ceiling: repeating Fam ≈ A·(n·dm/1000)² with factor A 1.90×10^-5 at the 24,000 r/min limiting speed raises the required axial preload to about 1.09 N; the reference-speed value 0.55 N is the thermal design point. Rating split for documentation: dynamic 1.78 kN (L10 life), static 1.92 kN (safety factor s0), fatigue limit 0.071 kN (adjusted life) — three different uses of three different numbers for BA 6, none interchangeable with another. Miniature handling note: the three BA components — shaft washer, housing washer and ball-cage assembly — are supplied loose and separate on contact, so mount the unit inside its housing recess before the shaft is offered; a dropped BA set scatters washers and balls that are nearly impossible to sort by eye, and a washer fitted reversed cannot be seen from outside once the cover is on. Service note at 6 mm bore: never grease-pack a BA bearing — one tiny dot of instrument oil on the ball set is enough, since the 4 g assembly will hydroplane its own cage out of position inside a flooded 14 mm OD recess.

Typical equipment & failure modes

Selection pitfalls — read before you substitute

• A 51-series bearing reacts thrust in one direction only — reversing positions need a mirrored single-direction pair or a 52-series double-direction unit; fitting a single BA 6 against two-way load lifts the loose washer off its raceway.
• The third digit grades the section: 511 light, then 512, 513 and 514 progressively taller and heavier at the same bore — select from 1.78/1.92 kN and the available 14 mm OD, never substitute a lighter series for a heavier one without rechecking C and C0.
• Heat the shaft washer to at most 120 °C for mounting, or press it via a sleeve on its ground bore — force applied through the housing washer or the ball set brinells the 1.78 kN track before first rotation.
• Identify the washers before fitting: the shaft washer has the ground, smaller bore and takes an interference fit on the 6 mm shaft, while the housing washer bore is larger and runs loose; swapping them locks the ball set and burns the tracks.
• There is no 51xxx coded size below 10 mm bore: the BA range is the miniature entry point for pure axial location, and at 6 mm the limit loads are small enough that shaft and housing squareness, not capacity, usually governs the design.
• Catalogue ratings are SKF PUB BU/P1 17000 figures for BA 6 as the miniature ba execution; other order numbers of the BA 6 size are different products and may carry different ratings or seating geometry — always quote the full designation when purchasing.