6405-ZZ 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 6405-ZZ model number is decoded

6405-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 heavy 64xx section (diameter series 4 of ISO 15), multiplying bore code 05 by five gives the 25 mm bore; the 80 mm outside diameter and 21 mm width follow the same boundary-dimension plan. For a rotating inner ring on a 25 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: 6405ZZ (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

• Sizes around 25 mm bore are normally pressed on cold with a sleeve against the inner-ring face; the press force must never route through the outer ring or the balls of 6405-ZZ.
• The 64xx heavy section at 25 mm bore exists for high radial load at moderate rpm; its 80 mm OD and 21 mm width demand a larger housing, and grease life at motor speeds is short — treat it as a low-speed, high-load choice.
• ZZ shields are non-contact: 6405-ZZ blocks chips and coarse dust but is not waterproof — do not install it expecting a pressure-wash seal, step up to 6405-2RS for that.
• Shielded 6405-ZZ 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 6405-ZZ drags the lip and overheats it.
• The housing bore for the 80 mm OD should be round within IT7; an oval bore pinches the outer ring of 6405-ZZ and shows up later as two-point loaded raceway wear.
• NTN catalogues the shielded version as 6405ZZ — 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 25 mm bore puts 6405 in NTN's light industrial range; the standard pressed-steel cage and CN clearance cover most fractional-horsepower motor and small-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 10000 r/min the grease limiting speed for 6405 covers most general-purpose industrial drives; the open or shielded execution can run continuously at this speed with standard lithium-soap grease.
• NTN rates 6405 at 38.5 kN dynamic (C) and 17.5 kN static (C0), 1.36 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 530 g, 6405 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 25×80×21 mm envelope of 6405 gives a D/d ratio of 3.20 and 27.5 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 38.5/17.5 kN load ratings, 1.36 kN fatigue load limit Cu NTN lists the grease limiting speed at 10000 r/min for this designation; oil-mist or jet lubrication raises the ceiling but requires a sealed-housing review. and 530 g mass here are NTN Ball and Roller Bearings CAT.No.2203-3/E figures for 6405ZZ on the 25×80×21 mm ISO 15 envelope; internal geometry and ratings legitimately differ between brands, so re-verify before substituting another manufacturer's 6405 in a rated drive.
• Standard catalogue stock of 6405 is the general-purpose execution; for low-noise motor duty NTN offers low-torque seal and special-grease variants in this size class, which are separate order numbers.
• 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.