7040 bearing: complete specifications & equivalents
The 7040 is a ISO 15 radial bearing sized 200 x 310 x 51 mm (bore x OD x width). Verify dimensions against the official catalog before ordering.
Specification table
| Parameter | Value |
|---|---|
| Brand | NTN |
| Bore diameter d | 200 mm |
| Outer diameter D | 310 mm |
| Width B | 51 mm |
| Material | GCr15 |
| Seal / shield | open |
| Internal clearance | CN |
| Tolerance class | P0 |
| Cage | brass |
| Basic dynamic load rating C | 279 kN |
| Basic static load rating C0 | 325 kN |
| Fatigue load limit Pu | 14.3 kN |
| Limiting speed (mechanical) | 2100 rpm |
| Operating temperature | -40 to +120 °C |
| Mass | 14000 g |
| Manufacturer designation | NTN 7040 |
| Standard | ISO 15 |
| Catalog version | NTN Ball and Roller Bearings CAT.No.2203E |
| Last verified | 2026-10-01 |
Source: catalog reference (NTN Ball and Roller Bearings CAT.No.2203E) · extracted 2026-10-01
Parameters extracted from the official NTN Ball and Roller Bearings catalogue (NTN Ball and Roller Bearings CAT.No.2203E); 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.
Dimensions in inches & 7000-series range
| Bore d | 7.874 in |
|---|---|
| Outer diameter D | 12.205 in |
| Width B | 2.008 in |
| ISO bore code | 40 |
| Radial section height (D−d)/2 | 55 mm |
| Smallest bore in 7000-series | 10 mm |
| Largest outer diameter in 7000-series | 420 mm |
| Width range across 7000-series | 8–65 mm |
| Bore position in 7000-series (smallest first) | 32 of 36 |
| Bore above smallest 7000-series size | 190 mm |
Cross references & equivalents
| Equivalent model | Brand | Match level | Note |
|---|---|---|---|
| 7040-BGM | SKF | partial Main dimensions match; tolerances, seals or internal clearance differ. | Same 200×310×51 mm envelope per ISO 15; catalogue load ratings differ by >10% — re-rate the application before substituting. |
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 7040 model number is decoded
7040 is the 200 mm bore member of NTN's standard-section 7000 single-row family, with a 310 mm outside diameter and 51 mm section width. Two fields make up the code — 70 is the single-row dimension series (standard-section 7000 single-row family) and 40 encodes the 200 mm bore (bore code x 5); with no letter after the digits it is the standard 30 deg contact-angle execution — the 40 deg version carries a B. Catalogue dynamic rating C is 279 kN against C0 325 kN — a C0/C ratio of 1.16 that is typical of an angular-contact contact ellipse. Choose the standard-section 7000 single-row family when the shaft needs a stiff locating support and the axial component is known to act mostly one way. Heat-mounting to 80-90 deg C is the clean route onto a 200 mm shaft; drive-fits through the balls transmit force through the contact ellipse and can brinell it.
Typical equipment & failure modes
Common applications
- large pump and turbine auxiliary shafts
- steel-plant conveyor and table roll drives
- wind-turbine and heavy-machinery auxiliaries
- heavy industrial gearbox main shafts
Known failure patterns
- false brinelling on the raceway contact ellipses when a preloaded spindle sits vibrating at standstill — visible as evenly spaced flute-like wear at ball pitch
- loss of preload after housing-fret or shaft creep, leaving the pair loose — ball skidding, cage rattle and a falling natural frequency follow
- pressed-steel cage pocket wear and rivet loosening after repeated ball skid at light load and high speed
- edge loading and early spalling from housing bores that are out of round or shoulders that are too small for the ring face
- contamination-induced denting — hard particles rolled into the contact ellipse become the initiation points for surface fatigue
Selection pitfalls — read before you substitute
- At this size the shaft fit, shoulder geometry and preload procedure dominate the outcome; a 200 mm bore bearing forgives nothing in a poorly machined housing.
- The standard 30 deg bearing and its B (40 deg) sibling share the envelope; picking between them is a load-direction decision, not a quality upgrade.
- A 7040 mounted the wrong way round still turns smoothly by hand; the failure shows up weeks later as raceway flaking on the unloaded-looking side.
- Substituting the B (40 deg) execution for the standard 30 deg bearing changes the axial/radial load split — the shaft position and the mating bearing see different forces even though the envelope is identical.
- Substituting the B (40 deg) execution for the standard 30 deg bearing changes the axial/radial load split — the shaft position and the mating bearing see different forces even though the envelope is identical.
- The 279/325 kN ratings and 14.3 kN Pu here are NTN Ball and Roller Bearings CAT.No.2203E figures for 7040; internal geometry legitimately differs between manufacturers, so re-verify ratings, contact angle and suffix before substituting another make on a rated drive.
Frequently asked questions
What are the dimensions and catalogue ratings of NTN 7040?
7040 is a single-row angular contact ball bearing to ISO 15: 200 mm bore, 310 mm outside diameter, 51 mm width (7.874 x 12.205 x 2.008 in). From NTN Ball and Roller Bearings CAT.No.2203E: C 279 kN, C0 325 kN and a 14.3 kN fatigue load limit Pu; the grease limiting speed is 2,100 r/min and the oil rating 2,800 r/min; mass about 14000 g.
How is the 7040 designation structured?
70 is the single-row dimension series (standard-section 7000 single-row family); 40 encodes the 200 mm bore (bore code x 5); with no letter after the digits it is the standard 30 deg contact-angle execution — the 40 deg version carries a B. The 310 mm OD and 51 mm width follow the ISO 15 boundary-dimension plan for that series.
Which axial direction does 7040 support?
One 7040 alone takes thrust in one direction only, along its 30 deg contact angle; reversing thrust calls for a second bearing or a factory-matched DB/DF/DT pair (the catalogue right-hand columns list the paired ratings). Radial load is always carried as a combined load through the angled contact.
What lubrication speeds does NTN print for 7040?
Per NTN Ball and Roller Bearings CAT.No.2203E, the grease limiting speed is 2,100 r/min and the oil rating 2,800 r/min. These are catalogue ceilings for a correctly mounted bearing with the stated lubricant; preload, fill quantity, ambient heat and paired arrangements all move the real limit.
What should be checked before substituting another make for 7040?
The 200/310/51 mm envelope is ISO 15 interchangeable, but internal geometry — contact angle, osculation, cage and shoulder details — is maker-specific. Re-verify C 279 kN / C0 325 kN, the speed figures, contact angle and suffix meaning against the donor catalogue before swapping on a rated drive.
Reviewed & verified by the MPN Base engineering desk against source catalog NTN Ball and Roller Bearings CAT.No.2203E on 2026-10-01. Read our editorial & correction policy.