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B21285 — SPRING,HELICAL,EXTENSION

✓ Government record, cited
— · COMPONENT
PRODUCT OVERVIEW

B21285: SPRING,HELICAL,EXTENSION.

The SPRING,HELICAL,EXTENSION is a the manufacturer industrial component. Key specifications include material: STEEL UNS K08500 OVERALL, end_style: SHORT TWISTED HOOK BOTH ENDS, design_type: CLOSED, hook_radius: 0.094 INCHES NOMINAL BOTH ENDS IN, coil_quantity: 10-1/2, inside_diameter: 0.210 INCHES NOMINAL IN. This part is cataloged in the U.S.

Government catalog under NSN 5360-00-316-4571, 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
B21285
NSN: 5360-00-316-4571
FSC: 5360 — Coil, Flat, Leaf, and Wire Springs
CAGE: 92208 — LITTON SYSTEMS INC ITEK OPTICAL SYSTEMS DIV (USA)
SPECIFICATIONS
materialSTEEL UNS K08500 OVERALL
end_styleSHORT TWISTED HOOK BOTH ENDS
design_typeCLOSED
hook_radius0.094 INCHES NOMINAL BOTH ENDS IN
coil_quantity10-1/2
inside_diameter0.210 INCHES NOMINAL IN
style_designatorCYLINDRICAL
spring_free_length0.69625 INCHES NOMINAL IN
coil_helix_directionRIGHT-HAND
coil_to_hook_inside_length0.188 INCHES NOMINAL BOTH ENDS IN
spring_free_outside_diameter0.250 INCHES NOMINAL IN
material_document_and_classificationQQ-W-470A FED SPEC SINGLE MATERIAL RESPONSE OVERALL A
NSN5360-00-316-4571
COMPONENT DIAGRAM
COMPONENT MAIN IC EDGE CONNECTOR No detailed specs available SPRING,HELICAL,EXTENSION TITLE COMPONENT PN B21285 MFR SPRING,HELICAL,EXTENSI
KEY FEATURES
•
SPRING FREE OUTSIDE DIAMETER: 0.250 INCHES NOMINAL IN
•
END STYLE: SHORT TWISTED HOOK BOTH ENDS
•
DESIGN TYPE: CLOSED
•
STYLE DESIGNATOR: CYLINDRICAL
•
MATERIAL DOCUMENT AND CLASSIFICATION: QQ-W-470A FED SPEC SINGLE MATERIAL RESPONSE OVERALL A
•
SPRING FREE LENGTH: 0.69625 INCHES NOMINAL IN
•
COIL TO HOOK INSIDE LENGTH: 0.188 INCHES NOMINAL BOTH ENDS IN
•
INSIDE DIAMETER: 0.210 INCHES NOMINAL IN
TECHNICAL CHARACTERISTICS
SPRING FREE OUTSIDE DIAMETER0.250 INCHES NOMINAL IN
END STYLESHORT TWISTED HOOK BOTH ENDS
DESIGN TYPECLOSED
STYLE DESIGNATORCYLINDRICAL
MATERIAL DOCUMENT AND CLASSIFICATIONQQ-W-470A FED SPEC SINGLE MATERIAL RESPONSE OVERALL A
SPRING FREE LENGTH0.69625 INCHES NOMINAL IN
COIL TO HOOK INSIDE LENGTH0.188 INCHES NOMINAL BOTH ENDS IN
INSIDE DIAMETER0.210 INCHES NOMINAL IN
COIL QUANTITY10-1/2
COIL HELIX DIRECTIONRIGHT-HAND
SUBSTITUTES & CROSS-REFERENCES 2
979-1A250Reference document
Same NSN cross-reference
Reference document — Secondary reference
62382Reference document
Same NSN cross-reference
Reference document — Design control — primary 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 B21285?
B21285 is a SPRING,HELICAL,EXTENSION.
What parts can replace B21285?
There are 2 known substitutes for B21285: 979-1A250, 62382. Substitute compatibility should be verified for your specific system.
What is the NSN for B21285?
B21285 is cataloged in the U.S. Government catalog under NSN 5360-00-316-4571. 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.