Product Overview
Nachi 7314-BMU-C3 Single-Row Angular Contact Ball Bearing - 40° Contact Angle, Brass Cage, C3 Clearance, 70x150x35mm
Condition
Unused NOS. Sourced from a government research facility. Outer ring stamped NACHI, JAPAN, and 7314BMUC3; original Nachi-Fujikoshi box present, marked MADE IN JAPAN with code B150224. Minor surface scuffs and scratches on the exterior consistent with storage; races show no visible wear or use. Brass cage intact with no deformation; open design, no seals or shields.
Carefully packed and shipped same or next business day from our Idaho warehouse. Honest equipment and straightforward service.
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Product Overview
Nachi Fujikoshi 7314-BMU-C3 is a single-row angular contact ball bearing engineered for heavy unidirectional axial thrust and radial composite loads. The 40° contact angle gives it higher axial load capacity than standard 15° or 25° designs. The machined high-strength brass cage (BM designation) provides stability at speed. The universally ground flush-face rings (U designation) allow this bearing to be paired into duplex sets - back-to-back (DB), face-to-face (DF), or tandem (DT) - without shims or spacers. C3 internal clearance accommodates thermal expansion during operation. Bore 70mm, outer diameter 150mm, width 35mm. Open design, no integral seals or shields.
Key Features
- Bore: 70mm inner diameter
- Outer diameter: 150mm
- Width: 35mm
- Contact angle: 40°, designed for heavy unidirectional axial thrust and radial composite loads
- Cage: Machined high-strength brass (BM) for stability at speed
- Universal ground / flush ground rings (U) - mountable in DB, DF, or DT duplex sets without shims or spacers
- C3 internal radial clearance - greater than normal, accommodates thermal expansion
- Limiting speed: 5,400 RPM under oil lubrication
- Open bearing - no seals or shields
- Outer ring stamped NACHI and JAPAN; part number 7314BMUC3 confirmed on outer race
Applications
- Replacing a failed angular contact bearing in a vertical pump or motor: the 40° contact angle handles the axial thrust load that standard radial bearings cannot sustain, and the C3 clearance accommodates shaft heating during run-up
- Building or rebuilding a high-speed spindle for CNC machining or precision grinding: the flush-ground U rings allow the technician to preload a DB or DF pair to a defined stiffness without introducing shimming errors
- Specifying bearings into new OEM equipment designs where shaft load direction is predominantly axial: the brass cage sustains speed and temperature conditions that pressed-steel cages may not
- Overhauling a gearbox or industrial motor where the original design calls specifically for a 7314-BMU-C3 and a substitute bearing with a different contact angle or clearance class would compromise the designed load path
Frequently Asked Questions
Can this bearing support axial load in both directions when used as a single unit?
No. A single angular contact ball bearing supports axial load in one direction only. For bidirectional axial loads, two bearings must be mounted in a paired configuration - back-to-back (DB) or face-to-face (DF). The universally ground U rings on this bearing are designed exactly for that purpose: two 7314-BMU-C3 units can be paired without shims or spacers.
Is this bearing suitable for environments with contamination or moisture?
This is an open bearing with no integral seals or shields. External sealing provisions in the housing are required for applications with contamination, moisture, or debris exposure.
What lubrication does this bearing require?
This bearing operates under oil or grease lubrication. Limiting speed under oil lubrication is 5,400 RPM. Proper lubrication method and type should be matched to the operating speed and temperature of the application.
Does this bearing come in its original box?
Yes. The bearing ships in its original Nachi-Fujikoshi box marked MADE IN JAPAN, model 7314BMUC3, code B150224.
What is the open-face design implication for mounting?
Open angular contact bearings require correct axial orientation during installation - the bearing must be mounted so the contact angle faces the applied thrust load direction. For duplex sets, the U (universally ground) face designation determines which faces are mated together for DB, DF, or DT configurations.
A precision bearing from Nachi Fujikoshi that has spent its years in a box rather than in a machine - contact angle intact, brass cage unmarked, races unrun. Whatever shaft it meets next gets the full working life the factory built into it.
