6307-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 6307-FAG model number is decoded

6307 is supplied open, without shields or seals, so the arrangement around it must supply and retain the lubricant. Within the medium 63xx section (diameter series 3 of ISO 15), multiplying bore code 07 by five gives the 35 mm bore; the 80 mm outside diameter and 21 mm width follow the same boundary-dimension plan. For a rotating inner ring on a 35 mm shaft under normal load, catalogue practice seats it on a k5 shaft fit with an H7 housing bore — confirm against the actual load direction and magnitude before committing. In the Schaeffler HR 1 catalogue this open execution carries the bare designation; protected variants are ordered separately with suffixes 2Z (steel shields), 2RZ (non-contact rubber seals) and 2RSR (lip-contact rubber seals).

Typical equipment & failure modes

Selection pitfalls — read before you substitute

• A 35 mm shaft for 6307 should be finished to Ra ≤ 1.6 µm with square seating faces; at this bore a scored or oval journal shows up directly as running noise and early raceway damage.
• The 63xx medium section at 35 mm bore gains dynamic rating through larger rolling elements on a 80 mm OD; the penalty is mass and a lower limiting speed than the 6207 — do not specify it for speed-critical shafts.
• Storage matters for open bearings: 6307-FAG leaves the factory with rust preventive only, so clean it and apply the service grease at assembly even if the rings look oily from the wrapper.
• Open bearings tolerate the highest speeds in the 6300-series but need a defined regreasing interval; run-to-failure lubrication is the dominant cause of early failure in open 6307 units.
• Deep-groove ball bearings tolerate only minutes of misalignment; if the 80 mm housing cannot be aligned, switch to a self-aligning type rather than shimming 6307-FAG.
• Suffixes stack in a defined order — clearance follows the seal code, e.g. 6307-FAG-C3. No clearance suffix means normal CN clearance.
• The open 6307 has no integral sealing; in the Schaeffler HR 1 catalogue the protected variants carry suffixes 2Z (two steel shields), 2RZ (two non-contact rubber seals) and 2RSR (two lip-contact rubber seals). Do not confuse FAG's 2RZ with a contact seal — the RZ lip does not touch the inner ring, which is why its speed capability stays close to the open bearing.
• FAG rates 6307 at 13600 r/min mechanical limiting speed (thermal reference speed 10900 r/min) — 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.
• The 35 mm bore puts 6307 in Schaeffler's general-purpose industrial range; the standard cage and CN clearance cover most electric-motor and pump duty, and FAG's X-life generation of these sizes carries higher ratings than legacy HR 1 printings — check the current eKatalog listing before reordering.
• FAG rates 6307 at 37 kN dynamic (C) and 19.1 kN static (C0); this upper-medium rating covers conveyor and gearbox drives, but under shock the pressed steel cage can become the limiting element — consider the machined brass cage (suffix M) for impact duty.
• At 471 g, 6307 requires a soft-jaw vise or arbor press for mounting — never hammer it onto the shaft, and support the opposite ring to avoid brinelling the raceways.
• The 35×80×21 mm envelope of 6307 gives a D/d ratio of 2.29 and 22.5 mm radial section height — a heavy FAG section 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 37/19.1 kN load ratings, mass 471 g here are Schaeffler HR 1 Rolling Bearings (Jan 2020) catalogue figures for 6307-C on the 35×80×21 mm ISO 15 envelope; internal geometry and ratings legitimately differ between brands, so re-verify before substituting another manufacturer's 6307 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.
• For hot shafts above roughly 100 °C continuous, consult Schaeffler about seal material and grease options for the 2RSR execution of 6307; the standard NBR lip is the economical general-duty choice, not the high-temperature one.
• Schaeffler's medias/eKatalog is the live source for the current execution of 6307: cage material, seal lip design and ratings can be revised between catalogue generations without any designation change.