6340 bearing: complete specifications & equivalents
The 6340 is a ISO 15 radial bearing sized 200 x 420 x 80 mm (bore x OD x width). Verify dimensions against the official catalog before ordering.
Specification table
| Parameter | Value |
|---|---|
| Brand | NSK |
| Bore diameter d | 200 mm |
| Outer diameter D | 420 mm |
| Width B | 80 mm |
| Material | GCr15 |
| Seal / shield | open |
| Internal clearance | CN |
| Tolerance class | P0 |
| Cage | steel |
| Basic dynamic load rating C | 415 kN |
| Basic static load rating C0 | 445 kN |
| Mass | 55300 g |
| Manufacturer designation | NSK 6340 |
| Standard | ISO 15 |
| Catalog version | NSK Rolling Bearings E1103 Part C |
| Last verified | 2026-09-24 |
Source: catalog reference (NSK Rolling Bearings E1103 Part C) · extracted 2026-09-24
Dimensions in inches & 6300-series range
| Bore d | 7.874 in |
|---|---|
| Outer diameter D | 16.535 in |
| Width B | 3.15 in |
| ISO bore code | 40 |
| Radial section height (D−d)/2 | 110 mm |
| Smallest bore in 6300-series | 10 mm |
| Largest outer diameter in 6300-series | 500 mm |
| Width range across 6300-series | 11–95 mm |
| Bore position in 6300-series (smallest first) | 32 of 34 |
| Bore above smallest 6300-series size | 190 mm |
Cross references & equivalents
| Equivalent model | Brand | Match level | Note |
|---|---|---|---|
| 6340 | ISO-INTERCHANGE | full Dimensions and internal design equivalent — standard interchange. | ISO 15 boundary-dimension interchange; ratings above are NSK E1103 values and differ by brand — verify per supplier. |
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 6340 model number is decoded
In the 6300-series (ISO 15 diameter series 3) the last two digits encode the bore: 6340 carries bore code 40 = 200 mm. Outside diameter 420 mm and width 80 mm come from the ISO 15 boundary-dimensions general plan. With no seal suffix the bearing is open: no shields or seals are fitted and lubrication is supplied by the application. For normal-load mounting with a rotating inner ring on a 200 mm shaft, typical catalogue practice is a m6 shaft seat with an H7 housing bore — verify against the actual load direction and magnitude.
Typical equipment & failure modes
Common applications
- industrial fans and blowers
- hoists and winches
- heavy conveyors
- pulp and paper machinery
Known failure patterns
- contamination wear from dust and dirt ingress through the open arrangement
- lubricant starvation when no regreasing interval is maintained
- false brinelling from vibration while the shaft is stationary
- fretting corrosion on a loose shaft seat
Selection pitfalls — read before you substitute
- Mount this 200 mm bore bearing by heating the inner ring (induction heater, max 120 °C) — never drive it home through the outer ring or balls, that brinells the raceways.
- The 63xx medium series gains rating at 200 mm bore through a 420 mm OD and 80 mm width; the heavier rolling elements also trade away some speed versus a 6240.
- The open 6340 has no lubricant retention: grease escapes and contaminants migrate straight into the 200×420×80 mm raceway, so specify a sealed arrangement for dusty or washdown duty.
- 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 6340 units.
- Shaft and housing fillets must clear the bearing chamfer so the 80 mm-wide ring seats square; provide an undercut or withdrawal groove instead of relying on an oversized radius.
- The open 6340 needs external sealing and application-supplied lubrication; in the NSK catalogue the protected variants are separate order numbers with suffixes ZZ (shields), VV (non-contact rubber seals) and DDU (contact rubber seals).
- The 415/445 kN ratings, mass 55300 g here are NSK Rolling Bearings E1103 Part C catalogue figures for 6340; this seal/size combination has no counterpart in the SKF 17000 extract used elsewhere on this site, so the page rests on a single manufacturer source — internal geometry and ratings legitimately differ between brands, so re-verify before substituting in a rated drive.
Frequently asked questions
What are the dimensions of a 6340 bearing?
A 6340 deep-groove ball bearing has a 200 mm bore, 420 mm outer diameter and 80 mm width (7.874 × 16.535 × 3.15 in), per ISO 15 boundary dimensions. It is an open bearing with no seals or shields.
How does the 6340 bore code work?
The last two digits of 6340 are bore code 40, giving 40 × 5 = 200 mm bore. The 420 mm outside diameter and 80 mm width follow the ISO 15 diameter series, not the bore code alone.
What does no suffix on 6340 mean?
A bare 6340 designation means open: no shields or seals, normal CN radial clearance and P0 normal tolerance unless further suffixes are ordered. The application must supply and retain the lubrication.
How does the 6300 compare with other series at the same 200 mm bore?
The '3' is the medium diameter series: 420×80 mm, 110.0 mm radial section at 200 mm bore, carrying more load than a 6240 but needing a larger housing bore and giving up some speed.
What is the NSK designation and catalogue data for 6340?
In the NSK Rolling Bearings catalogue (E1103 Part C) this size is listed as 6340 — the open (unsealed) execution, 200×420×80 mm per ISO 15. Quoted values: C 415 kN, C0 445 kN, mass 55300 g. The industry-neutral page spelling 6340 follows the seal-suffix convention used across this site, not NSK order-number spelling. Reference and limiting speeds are not tabulated in the E1103 dimension tables used here; consult NSK speed tables before high-speed service.
Reviewed & verified by the MPN Base engineering desk against source catalog NSK Rolling Bearings E1103 Part C on 2026-09-24. Read our editorial & correction policy.