YAT-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 YAT-204 model number is decoded

The YAR2 series order number YAT 204 is a SKF insert bearing (Y-bearing) for a 20 mm shaft: grub-screw insert bearing with the inner ring extended on one side, 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 YAT basic designation: set-screw shaft locking with the screws spaced 120 deg apart; YAT carries the one-side-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. with no -2F/-2RF suffix the order number denotes the open external execution of the YAR2 size — add external exclusion at the housing and plan relubrication intervals for dusty or wet surroundings. Envelope 20x47x25.5 mm (0.787x1.85x1.004 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 130 g. Static-first planning: the 0.257 kN of C0 per overall-width millimetre is the figure for belt tension peaks and rotor imbalance standstill loads on the 20 mm shaft, not the 12.7 kN L10 value. Grease-life arithmetic is dominated by speed: at dn approx 2.85x10^5 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. 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. Pitch-diameter arithmetic: dm = (20+47)/2 = 33.5 mm; at the 8,500 r/min limiting speed the ball set runs at dn approx 2.85x10^5, reduced from an open bearing mainly by seal lip friction and the life-long grease fill. Capacity density: 12.7 kN from 0.130 kg of bearing steel is about 97.692 kN per kilogram, and per width millimetre the 25.5 mm unit carries 0.498 kN of dynamic capacity. Single-extension fitting note: with the inner ring extended only on the locking side, orient the open (non-extended) face toward the shaft step or housing shoulder as the drawing shows — reversed, the set screws end up unsupported by the abutment and the shortened side offers no seal land at all. Service tip for YAT-204: dimpled or drilled shaft spots under the screw points are sometimes specified on shock duty, but the standard mounting relies on point indentation alone — never substitute longer screws that reach the 13.5 mm radial section.

Typical equipment & failure modes

Selection pitfalls — read before you substitute

• The 18.3 mm s1 dimension is the screw seating geometry inside the 11.5 mm of extended inner ring; a shaft step that crowds that side prevents the screws reaching the shaft squarely.
• Replacement discipline: a one-side YAT 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.
• 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.
• The 12.7/6.55 kN figures belong specifically to YAT 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.