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631B20-1 — RETAINER,HELICAL COMPRESSION SPR

✓ Government record, cited
— · ORING SEAL
PRODUCT OVERVIEW

631B20-1: RETAINER,HELICAL COMPRESSION SPR.

RETAINER,HELICAL COMPRESSION SPR. Key specifications include material: ALUMINUM ALLOY 6061, overall_height: 0.875 INCHES NOMINAL IN, flange_thickness: 0.125 INCHES NOMINAL IN, style_designator: IRREGULAR, surface_treatment: ANODIZE, body_inside_diameter: 0.265 INCHES NOMINAL IN. This part is cataloged in the U.S.

Government catalog under NSN 5340-01-064-1961, 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
631B20-1
NSN: 5340-01-064-1961
FSC: 5340 — Hardware, Commercial
CAGE: 78062 — SARGENT AEROSPACE & DEFENSE, LLC DBA SARGENT CONTROLS & AEROSPACE DIV SARGENT CONTROLS & AEROSPACE (USA)
SPECIFICATIONS
materialALUMINUM ALLOY 6061
overall_height0.875 INCHES NOMINAL IN
flange_thickness0.125 INCHES NOMINAL IN
style_designatorIRREGULAR
surface_treatmentANODIZE
body_inside_diameter0.265 INCHES NOMINAL IN
bolt_circle_diameter0.445 INCHES NOMINAL IN
body_outside_diameter0.522 INCHES NOMINAL IN
mounting_hole_diameter0.188 INCHES NOMINAL IN
casehardening_indicatorNOT CASEHARDENED
material_document_and_classificationQQ-A-225/8, ALLOY 6061, T651 FED SPEC SINGLE MATERIAL RESPONSE
surface_treatment_document_and_classificationMIL-A-8625, TYPE 1, CLASS 1 MIL SPEC SINGLE TREATMENT RESPONSE
NSN5340-01-064-1961
COMPONENT DIAGRAM
O-RING / SEAL — MATERIAL DETERMINES APPLICATION ID: — CROSS-SECTION CS: — SPECIFICATION Material: — Durometer: — Temp: — PN: 631B20-1 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
•
SURFACE TREATMENT DOCUMENT AND CLASSIFICATION: MIL-A-8625, TYPE 1, CLASS 1 MIL SPEC SINGLE TREATMENT RESPONSE
•
FLANGE THICKNESS: 0.125 INCHES NOMINAL IN
•
BODY OUTSIDE DIAMETER: 0.522 INCHES NOMINAL IN
•
STYLE DESIGNATOR: IRREGULAR
•
MATERIAL DOCUMENT AND CLASSIFICATION: QQ-A-225/8, ALLOY 6061, T651 FED SPEC SINGLE MATERIAL RESPONSE
•
MOUNTING HOLE DIAMETER: 0.188 INCHES NOMINAL IN
•
BODY INSIDE DIAMETER: 0.265 INCHES NOMINAL IN
TECHNICAL CHARACTERISTICS
OVERALL HEIGHT0.875 INCHES NOMINAL IN
SURFACE TREATMENT DOCUMENT AND CLASSIFICATIONMIL-A-8625, TYPE 1, CLASS 1 MIL SPEC SINGLE TREATMENT RESPONSE
FLANGE THICKNESS0.125 INCHES NOMINAL IN
BODY OUTSIDE DIAMETER0.522 INCHES NOMINAL IN
STYLE DESIGNATORIRREGULAR
MATERIAL DOCUMENT AND CLASSIFICATIONQQ-A-225/8, ALLOY 6061, T651 FED SPEC SINGLE MATERIAL RESPONSE
MOUNTING HOLE DIAMETER0.188 INCHES NOMINAL IN
BODY INSIDE DIAMETER0.265 INCHES NOMINAL IN
CASEHARDENING INDICATORNOT CASEHARDENED
BOLT CIRCLE DIAMETER0.445 INCHES NOMINAL IN
SUBSTITUTES & CROSS-REFERENCES 5
8-52N-587Reference document
Same NSN cross-reference
Reference document — Advisory reference — outside the item-of-supply concept
21089 FIND 20Reference document
Same NSN cross-reference
Reference document — Secondary reference
21835 FIND 30Reference document
Same NSN cross-reference
Reference document — Advisory reference — outside the item-of-supply concept
20402-002FIND25Reference document
Same NSN cross-reference
Reference document — Secondary reference
20402-002Reference document
Same NSN cross-reference
Reference document — Secondary reference
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 631B20-1?
631B20-1 is a RETAINER,HELICAL COMPRESSION SPR.
What parts can replace 631B20-1?
There are 5 known substitutes for 631B20-1: 8-52N-587, 21089 FIND 20, 21835 FIND 30 and 2 more. Substitute compatibility should be verified for your specific system.
What is the NSN for 631B20-1?
631B20-1 is cataloged in the U.S. Government catalog under NSN 5340-01-064-1961. 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.