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A78140-1 — SEAT,HELICAL COMPRESSION SPRING

✓ Government record, cited
— · ORING SEAL
PRODUCT OVERVIEW

A78140-1: SEAT,HELICAL COMPRESSION SPRING.

SEAT,HELICAL COMPRESSION SPRING. Key specifications include material: STEEL COMP 440A OR STEEL COMP 440B OR STEEL COMP 440C OR STEEL COMP 440F OR STEEL COMP 440FSE A, design_type: SOLID, end_diameter: 0.5300 INCHES MINIMUM AND 0.5350 INCHES MAXIMUM IN, overall_height: 0.2700 INCHES NOMINAL IN, style_designator: SEAT, surface_treatment: PASSIVATE. This part is cataloged in the U.S.

Government catalog under NSN 5340-01-360-7676, 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
A78140-1
NSN: 5340-01-360-7676
FSC: 5340 — Hardware, Commercial
CAGE: 9P5N5 — MOOG MILITARY AIRCRAFT LLC (USA)
SPECIFICATIONS
materialSTEEL COMP 440A OR STEEL COMP 440B OR STEEL COMP 440C OR STEEL COMP 440F OR STEEL COMP 440FSE A
design_typeSOLID
end_diameter0.5300 INCHES MINIMUM AND 0.5350 INCHES MAXIMUM IN
overall_height0.2700 INCHES NOMINAL IN
style_designatorSEAT
surface_treatmentPASSIVATE
first_step_diameter0.7300 INCHES MINIMUM AND 0.7350 INCHES MAXIMUM IN
material_document_and_classificationQQ-S-763, CLASS 440 FED SPEC SINGLE MATERIAL RESPONSE
NSN5340-01-360-7676
COMPONENT DIAGRAM
O-RING / SEAL — MATERIAL DETERMINES APPLICATION ID: — CROSS-SECTION CS: — SPECIFICATION Material: — Durometer: — Temp: — PN: A78140-1 MFR: OEM ⚠ VERIFY BEFORE ORDERING Wrong material = failure. Viton for oil/fuel, EPDM for water/steam, Buna-N for general purpose, Silicone for food-grade. Chemical incompatibility causes swelling, brittleness, or rapid degradation ✓ BROKER TIP Durometer (hardness) affects sealing pressure tolerance. Higher Shore A = harder = higher pressure. Standard durometer is 70A — verify if application requires different hardness PARTSTABLE TECHNICAL DRAWING — NOT TO SCALE
KEY FEATURES
•
FIRST STEP DIAMETER: 0.7300 INCHES MINIMUM AND 0.7350 INCHES MAXIMUM IN
•
END DIAMETER: 0.5300 INCHES MINIMUM AND 0.5350 INCHES MAXIMUM IN
•
DESIGN TYPE: SOLID
•
STYLE DESIGNATOR: SEAT
•
MATERIAL DOCUMENT AND CLASSIFICATION: QQ-S-763, CLASS 440 FED SPEC SINGLE MATERIAL RESPONSE
•
SURFACE TREATMENT: PASSIVATE
•
MATERIAL: STEEL COMP 440A OR STEEL COMP 440B OR STEEL COMP 440C OR STEEL COMP 440F OR STEEL COMP 440FSE A
TECHNICAL CHARACTERISTICS
OVERALL HEIGHT0.2700 INCHES NOMINAL IN
FIRST STEP DIAMETER0.7300 INCHES MINIMUM AND 0.7350 INCHES MAXIMUM IN
END DIAMETER0.5300 INCHES MINIMUM AND 0.5350 INCHES MAXIMUM IN
DESIGN TYPESOLID
STYLE DESIGNATORSEAT
MATERIAL DOCUMENT AND CLASSIFICATIONQQ-S-763, CLASS 440 FED SPEC SINGLE MATERIAL RESPONSE
SURFACE TREATMENTPASSIVATE
MATERIALSTEEL COMP 440A OR STEEL COMP 440B OR STEEL COMP 440C OR STEEL COMP 440F OR STEEL COMP 440FSE A
OTHER ITEMS IN FSC 5340 — Hardware, Commercial
Items in the same Federal Supply class. No interchangeability or substitution relationship is implied.
5340-00-000-0068 5340-00-000-0132 5340-00-000-8150 5340-00-001-1251 5340-00-001-1264 5340-00-001-1265 5340-00-001-1266 5340-00-001-1275
SUBSTITUTES & CROSS-REFERENCES

No substitute or cross-reference records for this part.

LIFECYCLE
NSN statusActive· U.S. Government catalog
Acquisition advice: Insurance item — stocked against contingency demandNo demilitarization required
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FREQUENTLY ASKED QUESTIONS
What is A78140-1?
A78140-1 is a SEAT,HELICAL COMPRESSION SPRING.
What is the NSN for A78140-1?
A78140-1 is cataloged in the U.S. Government catalog under NSN 5340-01-360-7676. 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.