61903-2RS-FAG bearing: complete specifications & equivalents

Specification table

Source: catalog reference (HR 1 Rolling Bearings (Jan 2020)) · extracted 2026-09-25

Parameters extracted from the official FAG Rolling Bearings catalogue (HR 1 Rolling Bearings (Jan 2020)); FAG® is a trademark of Schaeffler Technologies AG & Co. KG, used here for identification only — mpnbase is not an authorized FAG/Schaeffler distributor. Boundary dimensions are ISO 15 interchangeable; current production values may differ, verify at schaeffler.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 61903-2RS-FAG model number is decoded

In the 61900-series (diameter series 9 of ISO 15) the last two digits encode the bore: 61903 carries bore code 17 = 17 mm. Outside diameter 30 mm and width 7 mm come from the ISO 15 boundary-dimensions general plan. Suffix -2RS denotes two contact-type elastomer seals over a lifetime grease fill; the sealing lips add drag compared with open or shielded versions. For normal-load mounting with a rotating inner ring on a 17 mm shaft, typical catalogue practice is a j5 shaft seat with an H7 housing bore — verify against the actual load direction and magnitude. Schaeffler HR 1 catalogues the lip-contact sealed version as 61903-2RSR (FAG suffix 2RSR), mapped here from the industry-neutral -2RS spelling; it is greased for life and the contacting lip lowers the speed ceiling versus the open bearing.

Typical equipment & failure modes

Selection pitfalls — read before you substitute

• Mount this 17 mm bore bearing by heating the inner ring (induction heater, max 120 °C) — never drive it home through the outer ring or balls, that brinells the raceways.
• The 619xx thin section (6.5 mm section height at 17 mm bore) trades load capacity for compactness; stiff, accurately aligned seats are essential or edge loading will spall the raceway early.
• Contact seals add drag and heat: 61903-2RS-FAG runs slower and cooler-limited than the open 61903; rubber lips are generally limited to roughly 80–110 °C continuous depending on grease, and C3 clearance is the common hot-duty choice.
• Heat is the enemy of the sealed 61903-2RS: sustained running near the lip temperature limit hardens the rubber, after which grease escapes and dirt tracks in — watch the housing temperature in hot drives.
• The housing bore for the 30 mm OD should be round within IT7; an oval bore pinches the outer ring of 61903-2RS-FAG and shows up later as two-point loaded raceway wear.
• Measure the shaft, do not trust the drawing: a 17 mm nominal journal worn by even 0.02 mm turns an interference seat into a creeping fit that frets the bore of 61903-2RS-FAG.
• Schaeffler HR 1 lists the lip-contact sealed version as 61903-2RSR (FAG suffix 2RSR), mapped here from the industry-neutral -2RS spelling; it is greased for life and the contacting lip lowers the speed ceiling versus the open bearing. FAG's RSR lip material is NBR as standard — above roughly 100 °C continuous, consult Schaeffler for higher-temperature seal options.
• FAG rates 61903 at 12700 r/min mechanical limiting speed — electric-motor territory; prefer the open or 2Z execution (sealed 2RSR variants lose roughly a third of the thermal speed) and confirm grease life at the reference speed for continuous running.
• At 17 mm bore the 61903 sits in Schaeffler's small-bore range; HR 1 ships these sizes with a pressed steel or plastic cage and P0 tolerance as standard — for instrument or spindle accuracy order the P6/P5 variant explicitly, since P0 runout figures will not hold.
• At 4.59 kN dynamic load rating (C) and 2.56 kN static (C0), 61903 is a light-load FAG bearing: L10 life above a few kN of equivalent load is short, so size up to a 62-series on the same bore if the duty sees shock or frequent starts.
• At only 20 g, 61903 is a lightweight FAG bearing that can be handled by hand; still press it onto the shaft with a sleeve against the inner ring — never through the balls or outer ring.
• The 17×30×7 mm envelope of 61903 gives a D/d ratio of 1.76 and 6.5 mm radial section height — a standard FAG medium section balancing load capacity and speed; the standard cage is adequate up to the listed speeds and C3 clearance is the common hot-shaft choice.
• The 4.59/2.56 kN load ratings, mass 20 g here are Schaeffler HR 1 Rolling Bearings (Jan 2020) catalogue figures for 61903-2RSR on the 17×30×7 mm ISO 15 envelope; internal geometry and ratings legitimately differ between brands, so re-verify before substituting another manufacturer's 61903 in a rated drive. Where FAG has since released an X-life version of this size, its expanded C/C0 ratings supersede the HR 1 print values quoted here.
• Schaeffler's medias/eKatalog is the live source for the current execution of 61903: cage material, seal lip design and ratings can be revised between catalogue generations without any designation change.
• Mixing old and new FAG generations of the same designation in one arrangement is dimensionally acceptable, but where ratings matter — preloaded or matched sets — order both positions from the same generation and lot.