6326-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 6326-NTN model number is decoded

6326 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 26 by five gives the 130 mm bore; the 280 mm outside diameter and 58 mm width follow the same boundary-dimension plan. For a rotating inner ring on a 130 mm shaft under normal load, catalogue practice seats it on a m6 shaft fit with an H7 housing bore — confirm against the actual load direction and magnitude before committing. In the NTN catalogue this open execution carries the bare designation; protected variants are ordered separately with suffixes ZZ (shields), LLB/LLF (non-contact seals), LLH (low-torque contact seal) and LLU (contact seal).

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.
• Storage matters for open bearings: 6326-NTN 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 6326 units.
• Deep-groove ball bearings tolerate only minutes of misalignment; if the 280 mm housing cannot be aligned, switch to a self-aligning type rather than shimming 6326-NTN.
• Vibration during standstill brinells the raceways of a 130 mm bearing at ball spacing; if the machine sits idle next to running equipment, turn the shaft over periodically or isolate the arrangement.
• The open 6326 has no integral sealing; in the NTN 2203 catalogue the protected variants carry suffixes ZZ (non-contact steel shields), LLB/LLF (non-contact rubber seals), LLU (contact rubber seals) and LLH (a low-torque contact seal with higher speed capability than LLU). A JR or JRX suffix (printed for some thin-section sizes) denotes a pressed-steel cage, not a seal.
• The 130 mm bore places 6326 at the lower end of NTN's large-size range; at these diameters the pressed-steel cage is speed-limited and NTN commonly supplies a machined brass cage (suffix M) as an option. Verify cage material and relubrication interval with the NTN distributor, and do not extrapolate small-bore speed ratings to this size.
• NTN lists the grease limiting speed at 2400 r/min for 6326; this is a large or heavy-section size where centrifugal force and cage inertia cap the speed — for higher shaft speeds either step to a smaller bearing on the same bore or consult NTN for an oil-lubricated, machined-cage variant.
• NTN rates 6326 at 254 kN dynamic (C) and 214 kN static (C0), 11.7 kN fatigue load limit Cu; this is an upper heavy-load rating where the pressed-steel cage is not recommended — NTN supplies a machined brass cage (suffix M) and the static C0 must be verified against any shock or lifting loads the bearing sees during mounting.
• At 15300 g (15.3 kg), 6326 is a heavy 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 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 254/214 kN load ratings, 11.7 kN fatigue load limit Cu NTN lists the grease limiting speed at 2400 r/min for this designation; oil-mist or jet lubrication raises the ceiling but requires a sealed-housing review. and 15300 g mass here are NTN Ball and Roller Bearings CAT.No.2203-3/E figures for 6326 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.
• 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.
• NTN date-codes its packaging; rotate stock first-in-first-out, because the grease inside sealed units ages on the shelf — after three to five years of storage, check the grease condition before putting the bearing into service.