6203-RSR-NTN bearing: complete specifications & equivalents

Specification table

Source: catalog reference (NTN Ball and Roller Bearings CAT.No.2203-3/E (2024)) · extracted 2026-09-25

Parameters extracted from the official NTN Ball and Roller Bearings catalogue (NTN Ball and Roller Bearings CAT.No.2203-3/E (2024)); NTN® is a trademark of NTN Corporation, used here for identification only — mpnbase is not an authorized NTN distributor. Boundary dimensions are ISO 15 interchangeable; current production values may differ, verify at ntnglobal.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 6203-RSR-NTN model number is decoded

In the 6200-series (diameter series 2 of ISO 15) the last two digits encode the bore: 6203 carries bore code 17 = 17 mm. Outside diameter 40 mm and width 12 mm come from the ISO 15 boundary-dimensions general plan. Suffix -RSR denotes two low-friction non-contact elastomer seals; they keep coarse debris out with minimal drag but are not liquid-tight. 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. NTN's non-contact seal suffix is LLB/LLF (catalogue number 6203LLB), mapped here from the industry-neutral -RSR spelling; speed capability matches the open bearing but it is not liquid-tight.

Typical equipment & failure modes

Selection pitfalls — read before you substitute

• At 17 mm bore the ring mass is significant: heat 6203 on an induction heater (max 120 °C), never over an open flame, and plan puller access or a withdrawal sleeve now for the day it has to come off again.
• At 17 mm bore the 62xx light series is the workhorse section; its 40×12 mm envelope is what most motor and gearbox seats are machined for, so any alternative section must be checked against both this OD and this width, not the bore alone.
• RSR low-friction seals on 6203-RSR-NTN run faster than contact-seal 6203-2RS but let fine dust and moisture past the non-contact lip; in dirty or wet duty specify 6203-2RS instead.
• The non-contact lip of 6203-RSR-NTN does not retain a lifetime grease fill the way a contact seal does; confirm the regreasing interval for the 17 mm bore position before relying on it as sealed-for-life.
• A 17 mm bore listing showing the right d/D/B but no standard or precision-class reference may be a loose-tolerance import; measure bore/OD spread before fitting it to a machined shaft.
• Suffixes stack in a defined order — clearance follows the seal code, e.g. 6203-RSR-NTN-C3. No clearance suffix means normal CN clearance.
• NTN catalogues this low-friction non-contact seal as 6203LLB (suffix LLB), mapped here from the industry-neutral -RSR spelling. NTN rates its speed capability the same as the open bearing, but it is not liquid-tight — for wet or fine-dust duty step up to the LLU contact seal (industry-neutral -2RS).
• At 17 mm bore the 6203 sits in NTN's small-bore range; ABEC-1/P0 runout is standard, and the pressed-steel cage is adequate up to the grease limiting speed — for higher accuracy (spindles, instruments) ask NTN for a P6 or P5 tolerance-class listing before relying on catalogue P0 figures.
• NTN rates 6203 at 15000 r/min grease limiting speed — this is an electric-motor range; keep the grease fill at 25–35% of the free bearing volume and avoid mixing grease thickener types if regreasing through the seal lip.
• NTN rates 6203 at 10.6 kN dynamic (C) and 4.6 kN static (C0), 0.35 kN fatigue load limit Cu; this light-to-medium rating suits fractional-horsepower drives and instruments — for conveying or gearbox duty with shock loads, verify the equivalent dynamic load stays well below C.
• At 66 g, 6203 is light enough for hand assembly but should be pressed on with a fitting sleeve against the inner ring; do not strike the outer ring or cage with a hammer.
• The 17×40×12 mm envelope of 6203 gives a D/d ratio of 2.35 and 11.5 mm radial section height — a heavy section built for high-load, lower-speed duty; specifying it in a high-rpm motor generates excess heat and shortens grease life, so prefer a 62/63-series there.
• The 10.6/4.6 kN load ratings, 0.35 kN fatigue load limit Cu NTN lists the grease limiting speed at 15000 r/min for this designation; oil-mist or jet lubrication raises the ceiling but requires a sealed-housing review. and 66 g mass here are NTN Ball and Roller Bearings CAT.No.2203-3/E figures for 6203LLB on the 17×40×12 mm ISO 15 envelope; internal geometry and ratings legitimately differ between brands, so re-verify before substituting another manufacturer's 6203 in a rated drive.
• Factory-fill grease in NTN sealed units is a general-duty lithium-soap grease; food-grade, low-temperature and high-temperature fills are request options at order time, because LLU/LLB units are not meant to be opened and re-greased in the field.
• Standard catalogue stock of 6203 is the general-purpose execution; for low-noise motor duty NTN offers low-torque seal and special-grease variants in this size class, which are separate order numbers.