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3900621 — BEARING,SLEEVE

✓ Government record, cited
— · BALL BEARING
PRODUCT OVERVIEW

3900621: BEARING,SLEEVE.

The BEARING,SLEEVE is a the manufacturer industrial component. Key specifications include material: STEEL OUTER LAYER, corner_shape: SQUARE ALL CORNERS, overall_length: 20.0000 INCHES NOMINAL IN, surface_finish: 32.0 MICROINCHES INSIDE DIAMETER SURFACE OF BODY, style_designator: SEGMENTED, PLAIN, NO OUTSIDE FLANGES, body_inside_diameter: 24.0000 INCHES MINIMUM AND 24.0010 INCHES MAXIMUM IN. This part is cataloged in the U.S.

Government catalog under NSN 3120-00-143-5771, 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
3900621
NSN: 3120-00-143-5771
NIINs: 001435771, 012453193
FSC: 3120 — Bearings, Plain, Unmounted
CAGE: 16712 — SIEMENS ENERGY, INC. (USA)
SPECIFICATIONS
materialSTEEL OUTER LAYER
corner_shapeSQUARE ALL CORNERS
overall_length20.0000 INCHES NOMINAL IN
surface_finish32.0 MICROINCHES INSIDE DIAMETER SURFACE OF BODY
style_designatorSEGMENTED, PLAIN, NO OUTSIDE FLANGES
body_inside_diameter24.0000 INCHES MINIMUM AND 24.0010 INCHES MAXIMUM IN
body_outside_diameter27.9990 INCHES MINIMUM AND 28.0000 INCHES MAXIMUM IN
NSN3120-00-143-5771
COMPONENT DIAGRAM
BALL BEARING — SEAL TYPE DETERMINES MAINTENANCE OD: — · BORE: — · WIDTH: — SEAL: Open · PN: 3900621 · OEM ⚠ VERIFY BEFORE ORDERING ABEC grade: higher = tighter tolerance = higher cost. ABEC-1 is standard, ABEC-7+ for precision spindles. Open, shielded (ZZ), and sealed (2RS) versions have different max RPM ratings ✓ BROKER TIP 2RS = sealed for life (no maintenance). ZZ = shielded, re-greaseable. Open = must lubricate on install. Common interchange: 6205-2RS = 6205-2RSR = 6205-DDU (same bearing, different suffix) PARTSTABLE TECHNICAL DRAWING — NOT TO SCALE
KEY FEATURES
•
SURFACE FINISH: 63.0 MICROINCHES OUTSIDE DIAMETER SURFACE OF BODY
•
CORNER SHAPE: SQUARE ALL CORNERS
•
BODY OUTSIDE DIAMETER: 27.9990 INCHES MINIMUM AND 28.0000 INCHES MAXIMUM IN
•
STYLE DESIGNATOR: SEGMENTED, PLAIN, NO OUTSIDE FLANGES
TECHNICAL CHARACTERISTICS
SURFACE FINISH63.0 MICROINCHES OUTSIDE DIAMETER SURFACE OF BODY
SURFACE FINISH125.0 MICROINCHES RIGHT END SURFACE OF BODY
SURFACE FINISH32.0 MICROINCHES INSIDE DIAMETER SURFACE OF BODY
SURFACE FINISH125.0 MICROINCHES LEFT END SURFACE OF BODY
CORNER SHAPESQUARE ALL CORNERS
BODY OUTSIDE DIAMETER27.9990 INCHES MINIMUM AND 28.0000 INCHES MAXIMUM IN
STYLE DESIGNATORSEGMENTED, PLAIN, NO OUTSIDE FLANGES
OVERALL LENGTH20.0000 INCHES NOMINAL IN
BODY INSIDE DIAMETER24.0000 INCHES MINIMUM AND 24.0010 INCHES MAXIMUM IN
MATERIALTIN ALLOY INNER LAYER
SUBSTITUTES & CROSS-REFERENCES 1
D55896Same NSN cross-reference
Same NSN cross-reference
Also cataloged under this NSN
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 3900621?
3900621 is a BEARING,SLEEVE.
What parts can replace 3900621?
There is 1 known substitute for 3900621: D55896. Substitute compatibility should be verified for your specific system.
What is the NSN for 3900621?
3900621 is cataloged in the U.S. Government catalog under NSN 3120-00-143-5771. 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.