6326-ZZ bearing: complete specifications & equivalents

Specification table

Source: catalog reference (NSK Rolling Bearings E1103 Part C) · extracted 2026-09-24

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 6326-ZZ model number is decoded

In the 6300-series (diameter series 3 of ISO 15) the last two digits encode the bore: 6326 carries bore code 26 = 130 mm. Outside diameter 280 mm and width 58 mm come from the ISO 15 boundary-dimensions general plan. Suffix -ZZ denotes two non-contact metallic shields; they retain grease and block coarse debris but are not liquid-tight. For normal-load mounting with a rotating inner ring on a 130 mm shaft, typical catalogue practice is a m6 shaft seat with an H7 housing bore — verify against the actual load direction and magnitude. NSK catalogue order number: 6326ZZ (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 130 mm bore the ring mass is significant: heat 6326 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.
• The 63xx medium section at 130 mm bore gains dynamic rating through larger rolling elements on a 280 mm OD; the penalty is mass and a lower limiting speed than the 6226 — do not specify it for speed-critical shafts.
• ZZ shields are non-contact: 6326-ZZ blocks chips and coarse dust but is not waterproof — do not install it expecting a pressure-wash seal, step up to 6326-2RS for that.
• Do not wash 6326-ZZ in solvent before mounting: the grease inside the shielded cavity is the service fill, and solvent creeping past the shield gap strips it out.
• The housing bore for the 280 mm OD should be round within IT7; an oval bore pinches the outer ring of 6326-ZZ and shows up later as two-point loaded raceway wear.
• Never mix components between two 6326-ZZ units: rings, cage and balls are factory-matched and are not field-interchangeable, even between identical designations.
• NSK catalogues the shielded version as 6326ZZ — suffix ZZ, two non-contact steel shields. The industry-neutral page spelling is -ZZ; quote the NSK order number when buying through an NSK channel.
• The 130 mm bore places 6326 at the lower end of NSK's large-size range; at these diameters the pressed-steel cage is speed-limited and NSK commonly supplies a machined brass cage (suffix M) as an option. Verify cage material and relubrication interval with the NSK distributor, and do not extrapolate small-bore speed ratings to this size.
• NSK rates 6326 at 252 kN dynamic (C) and 214 kN static (C0); this is an extreme-load bearing at the top of the E1103 Part C single-row deep-groove range, where mounting, shaft stiffness and housing alignment dominate the achievable life. Consult NSK engineering for a full application review rather than relying on catalogue L10 alone.
• At 15200 g (15.2 kg), 6326 is a heavy NSK bearing that requires a crane or hoist for handling; induction-heat the inner ring (max 120 °C) and use a mechanical puller for removal — never apply heat directly to the balls or cage.
• The 130×280×58 mm envelope of 6326 gives a D/d ratio of 2.15 and 75.0 mm radial section height — a heavy NSK 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 252/214 kN load ratings, mass 15200 g here are NSK Rolling Bearings E1103 Part C catalogue figures for 6326ZZ on the 130×280×58 mm ISO 15 envelope; internal geometry and ratings legitimately differ between brands, so re-verify before substituting another manufacturer's 6326 in a rated drive. NSK does not tabulate reference or limiting speeds in the E1103 Part C dimension tables used for this page — consult NSK's separate speed-rating tables before high-speed service.
• NSK's VV non-contact seal keeps frictional torque close to the open 6326; in motor duty where heat build-up matters, VV is the usual compromise between debris protection and speed capability.
• When replacing a failed unit, inspect the shaft and housing seats before fitting the new 6326 — a new bearing pressed onto a worn or oval seat reproduces the original failure mode in a fraction of its expected life.