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

YAR 204-2F is SKF's 20 mm-bore grub-screw insert bearing with the inner ring extended on both sides in the YAR2 series — a Y-bearing with a spherically ground outside surface for static self-alignment inside a matching SKF Y-housing, boundary dimensions 20x47x31 mm. Wide-inner-ring deep-groove ball geometry carries the load: the extended inner ring gives the shaft grip and the seal lands, while the outer ring stays narrow and spherically ground on its outside surface. the YAR prefix names SKF grub-screw Y-bearings: two set screws in the extended inner ring lock the shaft at a 120 deg angle, and the inner ring extends symmetrically on both sides. 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. suffix -2F means an NBR rubber contact seal plus a plain pressed-steel flinger on EACH side: the lip rides the extended inner ring while the flinger sheds coarse contamination before it reaches the lip. 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: 8,500 r/min; mass 150 g. 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. Fillet discipline: the printed r_min 0.6 mm limit means shaft and housing fillets must stay under that radius; a fillet that bottoms the 20x47 mm insert on its chamfer tilts the whole spherical seat. Outer-vs-overall width: the outer ring is 14 mm wide inside the 31 mm total, so the extended inner ring accounts for 0.548 of the overall width (8.5 mm of axial projection per side). Mass-to-load ratio for YAR-204-2F: 11.811 g of catalogue mass per rated kN of C, and 7.5 g per millimetre of bore — useful when comparing executions of the same 20x47 mm envelope on the drawing. 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. Both-sides sealed order-number note: the two set screws clamp through dimpled recesses in the extended inner ring; tighten alternately to the catalogue procedure and retighten after the first run-in period, because the -2F flingers keep dust out but cannot compensate for a screw that walked loose. 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 204-2F; 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.