6307-ZZ-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 6307-ZZ-NTN model number is decoded

6307-ZZ carries two non-contact sheet-steel shields that hold the factory grease in and keep coarse debris out; they do not seal against liquids. 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. NTN catalogue order number: 6307ZZ (suffix ZZ), two non-contact steel shields, mapped here from the industry-neutral -ZZ spelling.

Typical equipment & failure modes

Selection pitfalls — read before you substitute

• At a 35 mm bore, a shaft-seat burr or an overtight setscrew can score the thin inner ring of 6307-ZZ-NTN; check shaft finish and runout (target Ra ≤ 1.6 µm) before pressing it home.
• 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.
• ZZ shields are non-contact: 6307-ZZ-NTN blocks chips and coarse dust but is not waterproof — do not install it expecting a pressure-wash seal, step up to 6307-2RS for that.
• Shielded 6307-ZZ-NTN units are typically greased for life; prying the shields out for regreasing usually bends them and leaves a gap that throws grease in service.
• Axial location must clamp the ring face, not the seal area: a shoulder or circlip bearing on the seal side of the 21 mm-wide ring of 6307-ZZ-NTN drags the lip and overheats it.
• Assign fits by which ring rotates: an interference shaft fit for a rotating inner ring; if the outer ring rotates instead, reverse the logic — a loose rotating ring creeps and frets its seat.
• NTN catalogues the shielded version as 6307ZZ — suffix ZZ, two non-contact steel shields. The industry-neutral page spelling is -ZZ; quote the NTN order number when buying through an NTN channel.
• The 35 mm bore puts 6307 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 7300 r/min the grease limiting speed for 6307 covers medium-duty industrial drives; the open or shielded execution can run continuously at this speed with standard lithium-soap grease.
• NTN rates 6307 at 37 kN dynamic (C) and 19.1 kN static (C0), 1.47 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 457 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 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 37/19.1 kN load ratings, 1.47 kN fatigue load limit Cu NTN lists the grease limiting speed at 7300 r/min for this designation; oil-mist or jet lubrication raises the ceiling but requires a sealed-housing review. and 457 g mass here are NTN Ball and Roller Bearings CAT.No.2203-3/E figures for 6307ZZ 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.
• 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.
• Order the C3 internal-clearance version (6307 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.