YARAG-204 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 YARAG-204 model number is decoded

The YAR2 series order number YARAG 204 is a SKF insert bearing (Y-bearing) for a 20 mm shaft: grub-screw insert bearing with the inner ring extended on both sides, built to the ISO 15 diameter-series envelope with a sphered OD of 47 mm. Inside is a sealed deep-groove ball set with an extended inner ring, two set screws 120 deg apart doing the shaft locking, and the sphered outer ring providing the unit's static alignment pivot. reading the YAR basic designation: set-screw shaft locking with the screws spaced 120 deg apart; YAR carries the symmetric, both-sides-extended inner ring. 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 AG suffix identifies the farm-duty variant of the range: sealed and flinger-protected for chaff and dust, with the catalogue deliberately derating its permissible speed versus the industrial 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: 1,800 r/min; mass 150 g. Inner-geometry cross-reference: the catalogue shoulder diameters (d1 28.2 mm) set the shaft-abutment and sleeve limits; an abutment larger than these numbers contacts the seal or the inner flinger. Grease-life arithmetic is dominated by speed: at dn approx 0.60x10^5 the sealed-for-life fill is planned for the catalogue's grease-life regime, which is why the AG variant caps speed so aggressively, and high-temperature mounts shorten both even when load is light. At the printed limiting speed of 1,800 r/min the mean diameter dm = 33.5 mm implies dn about 0.60x10^5 mm.r/min — the speed-demand figure used when comparing this insert with open deep-groove sizes of the same bore. Spherical-seat note in numbers: the 47 mm OD is ground spherical, so the self-aligning pivot happens on a circle roughly pi x 33.5 = 105.243 mm in mean circumference — keep that interface greased, because corrosion locking turns the pivot into a fixed misaligned mount. Pitch-diameter arithmetic: dm = (20+47)/2 = 33.5 mm; at the 1,800 r/min limiting speed the ball set runs at dn approx 0.60x10^5, reduced from an open bearing mainly by seal lip friction and the life-long grease fill. 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 YARAG 204; 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.