YAR-204-2RF 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 YAR-204-2RF model number is decoded

Listed in SKF 17000 chapter 2, YAR 204-2RF is a grub-screw insert bearing with the inner ring extended on both sides, 20x47x31 mm overall, whose convex spherical outer ring pivots in the spherical bore of a Y-pillow, Y-flange or take-up housing. Construction follows the Y-bearing principle: a capped and flinger-protected deep-groove ball insert, inner ring elongated for the screw points, outer ring convex-spherical for the housing seat. YAR is SKF's grub-screw insert design — an inner ring extended equally past the outer ring on both sides, the screws still 120 deg apart. the size code 204 carries the usual bore arithmetic — 20 mm — while the leading 2 marks the ISO 15 diameter series 2 sphered-OD envelope. the -2RF external design combines contact nitrile seals with rubberized additional flingers on both sides for a tighter labyrinth than the plain-flinger -2F execution. Envelope 20x47x31 mm (0.787x1.85x1.22 in), outer ring 14 mm wide, C 12.7 kN, C0 6.55 kN, Pu 0.28 kN. The catalogue publishes a single speed ceiling, the limiting speed: 5,000 r/min; mass 150 g. The s1 18.3 mm dimension is printed for the locking zone — the set-screw/collar seating reference — and it is verified at mounting, not recoverable from d/D/B alone. Bore-to-OD planning: OD 47 over bore 20 is a 2.35x step, while bore/overall-width gives 0.645; the spherical seat in the matching Y-housing must be specified to the 47 mm OD, not to a cylindrical housing bore. Grease-life arithmetic is dominated by speed: at dn approx 1.68x10^5 the sealed-for-life fill is planned for the catalogue's grease-life regime, which is why the limiting speed and the relubrication interval move together, and high-temperature mounts shorten both even when load is light. Load balance for documentation: C0 6.55 kN against C 12.7 kN gives a 0.516 ratio; mounted-unit positions with shock and standstill loading are normally checked on C0, while conveyor and fan duty are evaluated on the L10 figure. Rating split for the maintenance file: dynamic 12.7 kN (L10), static 6.55 kN (s0 shock check), fatigue 0.28 kN (adjusted life) — three separate uses for YAR 204-2RF, none interchangeable with another. Rubberized-flinger note: the -2RF coated throwers are vulcanized assemblies — never lever or hammer against the flinger when mounting, and press only on the inner ring when the bearing is fitted loose before the housing cap closes, or the flinger lip folds inward and grinds on the inner ring. Set-screw geometry on this size: the two 120 deg screws bear on the 20 mm shaft inside the 31 mm total width while the outer ring is only 14 mm wide, leaving the extended ring to carry the screw points clear of the ball track.

Typical equipment & failure modes

Selection pitfalls — read before you substitute

• The 18.3 mm s1 dimension is the screw seating geometry inside the 17 mm of extended inner ring; a shaft step that crowds that side prevents the screws reaching the shaft squarely.
• Do not specify the 20 mm grub-screw insert for a shaft harder than about 45 HRC without dimples: the screw points skate on hard surfaces and the unit creeps regardless of tightening torque.
• Replacement discipline: a YAR insert is not interchangeable with an eccentric-collar unit of the same envelope — the shaft may need spot-facing or collar space that does not exist.
• The 12.7/6.55 kN figures belong specifically to YAR 204-2RF; HV stainless, AG agricultural and VE495 zinc-plated variants of the same envelope publish derated values, so write the complete order number including suffixes on the purchase and maintenance records.