YAR-203-008-2F 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-203-008-2F model number is decoded

The YAR2 series order number YAR 203-008-2F is a SKF insert bearing (Y-bearing) for a 12.7 mm (0.5 in) 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 40 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. inch bore code -008 decodes as 0" +8/16, i.e. 12.7 mm; the metric coded size YAR 203 shares the same envelope but its bore is the metric value, not this one. the -2F external design pairs a nitrile contact seal with a plain sheet-steel thrower on both sides — a two-stage exclusion chain of flinger first, sealing lip second, typical of farm and conveyor duty. Envelope 12.7x40x27.4 mm (0.5x1.575x1.079 in), outer ring 12 mm wide, C 9.56 kN, C0 4.75 kN, Pu 0.2 kN. The catalogue publishes a single speed ceiling, the limiting speed: 9,500 r/min; mass 120 g. Speed ceiling of 9,500 r/min is the catalogue mechanical limit for THIS execution; seal lip and flinger drag, not steel fatigue, are normally what cap it, so real fan duty is planned well below it. Bore-to-OD planning: OD 40 over bore 12.7 is a 3.15x step, while bore/overall-width gives 0.464; the spherical seat in the matching Y-housing must be specified to the 40 mm OD, not to a cylindrical housing bore. Pitch-diameter arithmetic: dm = (12.7+40)/2 = 26.35 mm; at the 9,500 r/min limiting speed the ball set runs at dn approx 2.50x10^5, reduced from an open bearing mainly by seal lip friction and the life-long grease fill. Load balance for documentation: C0 4.75 kN against C 9.56 kN gives a 0.497 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. Mass-to-load ratio for YAR-203-008-2F: 12.552 g of catalogue mass per rated kN of C, and 9.449 g per millimetre of bore — useful when comparing executions of the same 12.7x40 mm envelope on the drawing. 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. Service tip for YAR-203-008-2F: 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 13.65 mm radial section.

Typical equipment & failure modes

Selection pitfalls — read before you substitute

• 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.
• Do not specify the 12.7 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 15.9 mm s1 dimension is the screw seating geometry inside the 15.4 mm of extended inner ring; a shaft step that crowds that side prevents the screws reaching the shaft squarely.
• Ordering discipline for the 12.7 mm size: the chapter lists several executions side by side (YAR2 locking style x seal package x application variant); a bare-number substitution needs a fresh dimension, speed and rating check rather than a like-for-like assumption.