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491993 — RETAINER,HELICAL COMPRESSION SPR

✓ Government record, cited
— · ORING SEAL
PRODUCT OVERVIEW

491993: RETAINER,HELICAL COMPRESSION SPR.

RETAINER,HELICAL COMPRESSION SPR. Key specifications include material: STEEL COMP 630, lip_thickness: 0.010 INCHES NOMINAL IN, overall_height: 1.570 INCHES NOMINAL IN, end_hole_diameter: 0.497 INCHES MINIMUM AND 0.503 INCHES MAXIMUM IN, body_inside_diameter: 0.629 INCHES MINIMUM AND 0.631 INCHES MAXIMUM IN, fsc_application_data: CONTROL ASSY,PRESSURE RATIO BLEED,ACFT ENGINE,2995001398687 743548. This part is cataloged in the U.S.

Government catalog under NSN 5340-00-920-3608, 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
491993
NSN: 5340-00-920-3608
FSC: 5340 — Hardware, Commercial
CAGE: 77445 — RTX CORPORATION DBA PRATT & WHITNEY DIV PRATT &WHITNEY (USA)
SPECIFICATIONS
materialSTEEL COMP 630
lip_thickness0.010 INCHES NOMINAL IN
overall_height1.570 INCHES NOMINAL IN
end_hole_diameter0.497 INCHES MINIMUM AND 0.503 INCHES MAXIMUM IN
body_inside_diameter0.629 INCHES MINIMUM AND 0.631 INCHES MAXIMUM IN
fsc_application_dataCONTROL ASSY,PRESSURE RATIO BLEED,ACFT ENGINE,2995001398687 743548
body_outside_diameter0.749 INCHES MINIMUM AND 0.751 INCHES MAXIMUM IN
mounting_hole_diameter0.183 INCHES MINIMUM AND 0.193 INCHES MAXIMUM IN
material_hardness_rating35.0 ROCKWELL C MINIMUM AND 42.0 ROCKWELL C MAXIMUM
material_document_and_classificationAMS 5643 ASSN STD SINGLE MATERIAL RESPONSE
NSN5340-00-920-3608
COMPONENT DIAGRAM
O-RING / SEAL — MATERIAL DETERMINES APPLICATION ID: — CROSS-SECTION CS: — SPECIFICATION Material: — Durometer: — Temp: — PN: 491993 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
•
FSC APPLICATION DATA: CONTROL ASSY,PRESSURE RATIO BLEED,ACFT ENGINE,2995001398687 743548
•
MATERIAL HARDNESS RATING: 35.0 ROCKWELL C MINIMUM AND 42.0 ROCKWELL C MAXIMUM
•
BODY OUTSIDE DIAMETER: 0.749 INCHES MINIMUM AND 0.751 INCHES MAXIMUM IN
•
MATERIAL DOCUMENT AND CLASSIFICATION: AMS 5643 ASSN STD SINGLE MATERIAL RESPONSE
•
MOUNTING HOLE DIAMETER: 0.183 INCHES MINIMUM AND 0.193 INCHES MAXIMUM IN
•
BODY INSIDE DIAMETER: 0.629 INCHES MINIMUM AND 0.631 INCHES MAXIMUM IN
•
LIP THICKNESS: 0.010 INCHES NOMINAL IN
TECHNICAL CHARACTERISTICS
OVERALL HEIGHT1.570 INCHES NOMINAL IN
FSC APPLICATION DATACONTROL ASSY,PRESSURE RATIO BLEED,ACFT ENGINE,2995001398687 743548
MATERIAL HARDNESS RATING35.0 ROCKWELL C MINIMUM AND 42.0 ROCKWELL C MAXIMUM
BODY OUTSIDE DIAMETER0.749 INCHES MINIMUM AND 0.751 INCHES MAXIMUM IN
MATERIAL DOCUMENT AND CLASSIFICATIONAMS 5643 ASSN STD SINGLE MATERIAL RESPONSE
MOUNTING HOLE DIAMETER0.183 INCHES MINIMUM AND 0.193 INCHES MAXIMUM IN
BODY INSIDE DIAMETER0.629 INCHES MINIMUM AND 0.631 INCHES MAXIMUM IN
LIP THICKNESS0.010 INCHES NOMINAL IN
MATERIALSTEEL COMP 630
END HOLE DIAMETER0.497 INCHES MINIMUM AND 0.503 INCHES MAXIMUM IN
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: Normally procured from the manufacturer (OEM)No demilitarization required
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FREQUENTLY ASKED QUESTIONS
What is 491993?
491993 is a RETAINER,HELICAL COMPRESSION SPR.
What is the NSN for 491993?
491993 is cataloged in the U.S. Government catalog under NSN 5340-00-920-3608. 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.
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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.