YAT-208 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-208 model number is decoded

Listed in SKF 17000 chapter 2, YAT 208 is a grub-screw insert bearing with the inner ring extended on one side, 40x80x36 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. YAT is SKF's grub-screw insert design — a single extended inner-ring side housing the two 120 deg set screws. the size code 208 carries the usual bore arithmetic — 40 mm (code 08 x 5) — while the leading 2 marks the ISO 15 diameter series 2 sphered-OD envelope. the bare designation means no factory seal package: unlike the -2F executions this bearing relies on enclosure by the Y-housing and its own re-greasing path, which is why it is normally specified inside well-sealed plummer and flange units. Envelope 40x80x36 mm (1.575x3.15x1.417 in), outer ring 21 mm wide, C 30.7 kN, C0 19 kN, Pu 0.8 kN. The catalogue publishes a single speed ceiling, the limiting speed: 4,800 r/min; mass 500 g. Fatigue-limit check: Pu 0.8 kN is the equivalent-load threshold under which the SKF adjusted-rating model credits very long life for YAT 208 — most belt-driven mounted-unit loads sit comfortably under 2.606 % of C. Inner-geometry cross-reference: the catalogue shoulder diameters (d1 51.8 mm) set the shaft-abutment and sleeve limits; an abutment larger than these numbers contacts the seal or the inner flinger. Imperial procurement cross-check: 1.575 in bore, 3.15 in OD, 1.417 in overall width; the 500 g mass converts to 0.500 kg (17.6 oz) for the bill of materials. Grease-life arithmetic is dominated by speed: at dn approx 2.88x10^5 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. Bore-to-OD planning: OD 80 over bore 40 is a 2x step, while bore/overall-width gives 1.111; the spherical seat in the matching Y-housing must be specified to the 80 mm OD, not to a cylindrical housing bore. 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. Set-screw geometry on this size: the two 120 deg screws bear on the 40 mm shaft inside the 36 mm total width while the outer ring is only 21 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

• Do not specify the 40 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 25.3 mm s1 dimension is the screw seating geometry inside the 15 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.
• Catalogue ratings belong to YAT 208 as the grub one open execution; other order numbers of the YAT 208 size are different articles (open vs sealed, plain vs rubberized flinger, stainless vs carbon steel) and may carry different ratings or speeds — always quote the full designation.