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Q-12378 — ROLLER,BEARING

✓ Government record, cited
— · TAPERED BEARING
PRODUCT OVERVIEW

Q-12378: ROLLER,BEARING.

The ROLLER,BEARING is a the manufacturer industrial component. Key specifications include material: STEEL COMP E52100 OVERALL, overall_length: 0.8540 INCHES MINIMUM AND 0.8640 INCHES MAXIMUM IN, special_features: ROCKWELL HARDNESS C 60.0 MIN 64.0 MAX, style_designator: CYLINDRICAL ROLLER, FLAT ENDS, rolling_element_diameter: 0.3123 INCHES MINIMUM AND 0.3125 INCHES MAXIMUM IN. This part is cataloged in the U.S.

Government catalog under NSN 3110-01-155-6124, indicating validated use in U.S. government and defense logistics supply chains. Available through authorized enterprise resellers and TPM (Third Party Maintenance) channels.

Verify compatibility with your specific system configuration before ordering.

WHERE IT FITS
Q-12378
NSN: 3110-01-155-6124
FSC: 3110 — Bearings, Antifriction, Unmounted
CAGE: 60380 — TIMKEN AEROSPACE, INC DBA TORRINGTON PRODUCT (USA)
SPECIFICATIONS
materialSTEEL COMP E52100 OVERALL
overall_length0.8540 INCHES MINIMUM AND 0.8640 INCHES MAXIMUM IN
special_featuresROCKWELL HARDNESS C 60.0 MIN 64.0 MAX
style_designatorCYLINDRICAL ROLLER, FLAT ENDS
rolling_element_diameter0.3123 INCHES MINIMUM AND 0.3125 INCHES MAXIMUM IN
NSN3110-01-155-6124
COMPONENT DIAGRAM
TAPERED ROLLER BEARING — CUP & CONE ASSEMBLY CAGE CUP BORE CONE OD: — · BORE: — · WIDTH: — Single Row · PN: Q-12378 · OEM ⚠ VERIFY BEFORE ORDERING Cup and cone sold separately — verify you are ordering BOTH parts or the correct component. Always replace cup and cone together — mismatched wear = premature failure ✓ BROKER TIP Taper angle determines axial load capacity. Steeper angle = higher axial load rating. Timken series numbers indicate dimensions — cross-reference carefully PARTSTABLE TECHNICAL DRAWING — NOT TO SCALE
KEY FEATURES
•
ROLLING ELEMENT DIAMETER: 0.3123 INCHES MINIMUM AND 0.3125 INCHES MAXIMUM IN
•
STYLE DESIGNATOR: CYLINDRICAL ROLLER, FLAT ENDS
•
MATERIAL: STEEL COMP E52100 OVERALL
TECHNICAL CHARACTERISTICS
ROLLING ELEMENT DIAMETER0.3123 INCHES MINIMUM AND 0.3125 INCHES MAXIMUM IN
STYLE DESIGNATORCYLINDRICAL ROLLER, FLAT ENDS
OVERALL LENGTH0.8540 INCHES MINIMUM AND 0.8640 INCHES MAXIMUM IN
SPECIAL FEATURESROCKWELL HARDNESS C 60.0 MIN 64.0 MAX
MATERIALSTEEL COMP E52100 OVERALL
OTHER ITEMS IN FSC 3110 — Bearings, Antifriction, Unmounted
Items in the same Federal Supply class. No interchangeability or substitution relationship is implied.
3110-00-001-1937 3110-00-001-1938 3110-00-001-4661 3110-00-001-4662 3110-00-001-4689 3110-00-001-4722
SUBSTITUTES & CROSS-REFERENCES 1
SR-903Reference document
Same NSN cross-reference
Reference document — Secondary reference
LIFECYCLE
NSN statusActive· U.S. Government catalog
Acquisition advice: Normally procured from the manufacturer (OEM)No demilitarization required
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FREQUENTLY ASKED QUESTIONS
What is Q-12378?
Q-12378 is a ROLLER,BEARING.
What parts can replace Q-12378?
There is 1 known substitute for Q-12378: SR-903. Substitute compatibility should be verified for your specific system.
What is the NSN for Q-12378?
Q-12378 is cataloged in the U.S. Government catalog under NSN 3110-01-155-6124. This indicates validated use in U.S. government and defense supply chains.
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✓ PartsTable — the parts reference. Every fact cited to its source.
PartsTable Design LLC · partstable.com
U.S. Government catalog: edition PUBLOGDVD v12.0.0 (OCT 2026), edition date 2026-10-01, retrieved 2026-10-18.
PartsTable commercial catalog: edition Unified commercial catalog snapshot through 2026-09-28, edition date not on file, retrieved 2026-09-28.