6310-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 6310-RSR-NTN model number is decoded

In the 6300-series (diameter series 3 of ISO 15) the last two digits encode the bore: 6310 carries bore code 10 = 50 mm. Outside diameter 110 mm and width 27 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 50 mm shaft, typical catalogue practice is a k5 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 6310LLB), 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

• Temperature rise and interference fits consume internal clearance on this 50 mm bore: a CN bearing on a tight, hot shaft can lose all residual clearance — size 6310 with C3 for those conditions.
• The 63xx medium section at 50 mm bore gains dynamic rating through larger rolling elements on a 110 mm OD; the penalty is mass and a lower limiting speed than the 6210 — do not specify it for speed-critical shafts.
• The low-drag lip of 6310-RSR-NTN barely touches the inner ring; after long shelf storage the grease can separate, so rotate the rings by hand and confirm smooth, silent running before fitting.
• The non-contact lip of 6310-RSR-NTN does not retain a lifetime grease fill the way a contact seal does; confirm the regreasing interval for the 50 mm bore position before relying on it as sealed-for-life.
• Shaft and housing fillets must clear the bearing chamfer so the 27 mm-wide ring seats square; provide an undercut or withdrawal groove instead of relying on an oversized radius.
• Deep-groove ball bearings tolerate only minutes of misalignment; if the 110 mm housing cannot be aligned, switch to a self-aligning type rather than shimming 6310-RSR-NTN.
• NTN catalogues this low-friction non-contact seal as 6310LLB (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).
• The 50 mm bore puts 6310 in NTN's general-purpose industrial range; the standard pressed-steel cage and CN clearance cover most electric-motor and pump duty, but for continuous high-speed use specify the LLH low-torque seal (not LLU) and confirm the housing allows the listed limiting speed.
• At 5000 r/min the grease limiting speed for 6310 covers medium-duty industrial drives; the open or shielded execution can run continuously at this speed with standard lithium-soap grease.
• NTN rates 6310 at 68.5 kN dynamic (C) and 38.5 kN static (C0), 2.99 kN fatigue load limit Cu; this upper-medium rating covers conveyor and gearbox drives, but at these loads the pressed-steel cage can be the limiting factor under shock — consider the machined brass cage (suffix M) for impact duty.
• At 1070 g (1.1 kg), 6310 needs mechanical handling for mounting; NTN recommends induction heating the inner ring (max 120 °C) rather than pressing cold, and a lifting eye if the housing is pre-assembled.
• The 50×110×27 mm envelope of 6310 gives a D/d ratio of 2.20 and 30.0 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 68.5/38.5 kN load ratings, 2.99 kN fatigue load limit Cu NTN lists the grease limiting speed at 5000 r/min for this designation; oil-mist or jet lubrication raises the ceiling but requires a sealed-housing review. and 1070 g mass here are NTN Ball and Roller Bearings CAT.No.2203-3/E figures for 6310LLB on the 50×110×27 mm ISO 15 envelope; internal geometry and ratings legitimately differ between brands, so re-verify before substituting another manufacturer's 6310 in a rated drive.
• Order the C3 internal-clearance version (6310 with C3 after the seal code) when the shaft fit is tight or the shaft-to-housing temperature gradient exceeds roughly 10 °C — the residual clearance after mounting, not the catalogue CN figure, decides service life.
• NTN's pressed-steel cage (no cage suffix) is the quiet standard for this size; for sustained running close to the limiting speed or for heavy shock duty, ask the NTN channel whether a machined-cage execution of 6310 is listed.