51317-SKF 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 51317-SKF model number is decoded

51317 is SKF's 85 mm-bore single-direction thrust ball bearing in the 51300 series to the ISO 104 dimension plan, with a flat housing seating surface, measuring 85×150×49 mm. The separable set comprises a shaft washer (ground bore, tight fit on the shaft), a loose-bore housing washer and one ball-cage assembly, reacting axial force in one direction and carrying no radial load. in the 51xxx designation the first 1 marks a single-direction bearing with a flat housing seating surface; the third digit 1–4 grades the dimension series from the light 511 section through the heavy 514 section. the final two digits 17 encode the bore as 85 mm (code 17 × 5), the standard SKF bore-code rule shared with radial bearings. with no cage suffix this is the standard execution with a stamped sheet-steel ball-cage assembly (pressed cage) — the light, quiet and economical cage for small and medium thrust-ball sizes. Envelope 85×150×49 mm (3.346×5.906×1.929 in), 32.5 mm radial section, C 174 kN, C0 405 kN, Pu 14 kN. reference speed 1,600 r/min (thermal) and limiting speed 2,200 r/min (mechanical), catalogue mass 3550 g. Rating split for documentation: dynamic 174 kN (L10 life), static 405 kN (safety factor s0), fatigue limit 14 kN (adjusted life) — three different uses of three different numbers for 51317, none interchangeable with another. Imperial cross-check for procurement drawings: 3.346 in bore, 5.906 in OD, 1.929 in height, and the 3550 g catalogue mass converts to 3.550 kg (125.2 oz). Speed band width for this size is 600 r/min between reference and limiting (1.38× ratio); lubrication, preload and heat removal decide where inside that band 51317 can actually run. Section proportions: the 32.5 mm radial section compares with 85 mm of bore (section/bore ≈ 0.38) and the 49 mm height is 1.51× that section — the proportions that identify the 51300 envelope at a glance. Envelope economics: the 49 mm axial height over a 32.5 mm radial section yields 3.6 kN of dynamic capacity per height millimetre, and the bearing weighs 3550 g for 174 kN C — about 20 g per rated kN. Execution note for this order number: the flat housing seating surface must be machined square to the shaft axis and supported across the full washer face — unlike the sphered 53-series execution this pressed-cage 51-series bearing has no self-aligning capability at all, so seat squareness is checked at mounting, not compensated in service. Inspection after removal of a 49 mm-high stack means checking both washer faces: the loose housing washer often shows the first false-brinell marks under machine vibration even though the tight shaft washer carries the rotating load of 174 kN C.

Typical equipment & failure modes

Selection pitfalls — read before you substitute

• On vertical shafts retain the loose housing washer positively with a cover or ring and verify the grease fill does not drain out of the 49 mm stack; thrust-ball bearings on horizontal shafts should have the shaft washer (the tight one) against the rotating element.
• The three components are separable and interchangeable within the ISO 104 size, but keep this bearing's parts together in service and never combine washers from different manufacturers or a worn washer with a new ball set.
• Identify the washers before fitting: the shaft washer has the ground, smaller bore and takes an interference fit on the 85 mm shaft, while the housing washer bore is larger and runs loose; swapping them locks the ball set and burns the tracks.
• The 51317 is a pure axial bearing: it must never be subjected to radial load — any radial force on the 85 mm shaft has to be carried by a radial bearing mounted alongside it.
• Catalogue ratings are SKF PUB BU/P1 17000 figures for 51317 as the single flat pressed steel execution; other order numbers of the 51317 size are different products and may carry different ratings or seating geometry — always quote the full designation when purchasing.