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4001278 — CAPACITOR,FIXED,ELECTROLYTIC

✓ Government record, cited
— · MRO · MRO_GENERAL
PRODUCT OVERVIEW

4001278: CAPACITOR,FIXED,ELECTROLYTIC.

The CAPACITOR,FIXED,ELECTROLYTIC is a the manufacturer cache protection component designed to preserve data integrity during power loss events in enterprise server and storage controller environments. Key specifications include material: STEEL COMP E52100 INNER RING, body_style: W/O MTG FACILITIES, TERMINAL(S) ON ONE END, bore_shape: STRAIGHT, body_length: 4.125 INCHES NOMINAL IN, body_diameter: 3.000 INCHES NOMINAL IN, bore_diameter: 1.3778 INCHES MINIMUM AND 1.3780 INCHES MAXIMUM IN. This part is cataloged in the U.S.

Government catalog under NSN 3110-00-416-9423, 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
MRO→ MRO_GENERAL→ 4001278
NSN: 3110-00-416-9423
NIINs: 004169423, 010370173, 012301949
FSC: 3110 — Bearings, Antifriction, Unmounted
CAGE: 77445 — RTX CORPORATION DBA PRATT & WHITNEY DIV PRATT &WHITNEY (USA)
SPECIFICATIONS
materialSTEEL COMP E52100 INNER RING
body_styleW/O MTG FACILITIES, TERMINAL(S) ON ONE END
bore_shapeSTRAIGHT
body_length4.125 INCHES NOMINAL IN
body_diameter3.000 INCHES NOMINAL IN
bore_diameter1.3778 INCHES MINIMUM AND 1.3780 INCHES MAXIMUM IN
overall_width0.5462 INCHES MINIMUM AND 0.5512 INCHES MAXIMUM IN
surface_finishUNGROUND
locating_featureNONLOCATING
special_featuresINNER AND OUTER RINGS AND ROLLER MATL VACUUM DEGASSED PROCESS
style_designatorSINGLE ROW, ONE-DIRECTION LOCATING, ONE LIP INNER RING, ONE LIP OUTER RING WITH ONE ROLLER RETAINMENT RING ON OUTER, SEPARABLE
precious_materialSILVER
NSN3110-00-416-9423
COMPONENT DIAGRAM
TAPERED ROLLER BEARING — CUP & CONE ASSEMBLY CAGE CUP BORE CONE OD: — · BORE: — · WIDTH: — Single Row · PN: 4001278 · 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
•
RETAINER FABRICATION METHOD: MACHINED
•
INTERNAL CLEARANCE: 0.0007 INCHES MINIMUM AXIAL AND 0.0022 INCHES MAXIMUM AXIAL IN
•
LOCATING FEATURE: NONLOCATING
•
SURFACE FINISH: UNGROUND
•
PRECIOUS MATERIAL: SILVER
•
STYLE DESIGNATOR: SINGLE ROW, ONE-DIRECTION LOCATING, ONE LIP INNER RING, ONE LIP OUTER RING WITH ONE ROLLER RETAINMENT RING ON OUTER, SEPARABLE
•
OVERALL OUTSIDE DIAMETER: 2.4406 INCHES MINIMUM AND 2.4409 INCHES MAXIMUM IN
TYPICAL APPLICATIONS
  • RAID cache protection during power loss events
  • Write-back cache enablement for storage controllers
  • Enterprise server data integrity assurance
  • Hot-swap battery/capacitor replacement in production
TECHNICAL CHARACTERISTICS
RETAINER FABRICATION METHODMACHINED
INTERNAL CLEARANCE0.0007 INCHES MINIMUM AXIAL AND 0.0022 INCHES MAXIMUM AXIAL IN
LOCATING FEATURENONLOCATING
SURFACE FINISHUNGROUND
PRECIOUS MATERIALSILVER
STYLE DESIGNATORSINGLE ROW, ONE-DIRECTION LOCATING, ONE LIP INNER RING, ONE LIP OUTER RING WITH ONE ROLLER RETAINMENT RING ON OUTER, SEPARABLE
OVERALL WIDTH0.5462 INCHES MINIMUM AND 0.5512 INCHES MAXIMUM IN
OVERALL OUTSIDE DIAMETER2.4406 INCHES MINIMUM AND 2.4409 INCHES MAXIMUM IN
BORE SHAPESTRAIGHT
SPECIAL FEATURESINNER AND OUTER RINGS AND ROLLER MATL VACUUM DEGASSED PROCESS
SUBSTITUTES & CROSS-REFERENCES 4
4001277Same NSN cross-reference
Same NSN cross-reference
Also cataloged under this NSN
4044745Reference document
Same NSN cross-reference
Reference document — Secondary reference
4032003Reference document
Same NSN cross-reference
Reference document — Secondary reference
4001276Reference document
Same NSN cross-reference
Reference document — Secondary reference
LIFECYCLE
NSN statusCancelled· U.S. Government catalog
No demilitarization required
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FREQUENTLY ASKED QUESTIONS
What is 4001278?
4001278 is a CAPACITOR,FIXED,ELECTROLYTIC. It is classified as a MRO (MRO_GENERAL).
What parts can replace 4001278?
There are 4 known substitutes for 4001278: 4001277, 4044745, 4032003 and 1 more. Substitute compatibility should be verified for your specific system.
What is the NSN for 4001278?
4001278 is cataloged in the U.S. Government catalog under NSN 3110-00-416-9423. 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.