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27640-6591 — SEAL,PLAIN ENCASED

✓ Government record, cited
— · ORING SEAL
PRODUCT OVERVIEW

27640-6591: SEAL,PLAIN ENCASED.

The SEAL,PLAIN ENCASED is a the manufacturer industrial component. Key specifications include material: RUBBER SYNTHETIC SEALING ELEMENT, case_style: SQUARE, seal_width: 0.250 INCHES NOMINAL IN, temp_rating: 250.0 FAHRENHEIT DEGF, surface_treatment: ANODIZE CASE, housing_bore_diameter: 3.940 INCHES NOMINAL IN. This part is cataloged in the U.S.

Government catalog under NSN 5330-00-944-5851, 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
27640-6591
NSN: 5330-00-944-5851
FSC: 5330 — Packing and Gasket Materials
CAGE: 73680 — GARLOCK SEALING TECHNOLOGIES LLC DBA GARLOCK SEALING TECHNOLOGIES LLC (USA)
SPECIFICATIONS
materialRUBBER SYNTHETIC SEALING ELEMENT
case_styleSQUARE
seal_width0.250 INCHES NOMINAL IN
temp_rating250.0 FAHRENHEIT DEGF
surface_treatmentANODIZE CASE
housing_bore_diameter3.940 INCHES NOMINAL IN
sealing_element_styleANGULAR
accommodated_shaft_diameter3.250 INCHES NOMINAL IN
material_document_and_classification9100 FSCM 73680 MFR REF SINGLE MATERIAL RESPONSE SEALING ELEMENT
accommodated_shaft_maximum_rated_speed3000 FEET PER MINUTE FT
NSN5330-00-944-5851
COMPONENT DIAGRAM
O-RING / SEAL — MATERIAL DETERMINES APPLICATION ID: — CROSS-SECTION CS: — SPECIFICATION Material: — Durometer: — Temp: — PN: 27640-6591 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
•
TEMP RATING: 250.0 FAHRENHEIT DEGF
•
SEAL WIDTH: 0.250 INCHES NOMINAL IN
•
SEALING ELEMENT STYLE: ANGULAR
•
HOUSING BORE DIAMETER: 3.940 INCHES NOMINAL IN
•
MATERIAL DOCUMENT AND CLASSIFICATION: 9100 FSCM 73680 MFR REF SINGLE MATERIAL RESPONSE SEALING ELEMENT
•
ACCOMMODATED SHAFT MAXIMUM RATED SPEED: 3000 FEET PER MINUTE FT
•
CASE STYLE: SQUARE
•
ACCOMMODATED SHAFT DIAMETER: 3.250 INCHES NOMINAL IN
TECHNICAL CHARACTERISTICS
TEMP RATING250.0 FAHRENHEIT DEGF
SEAL WIDTH0.250 INCHES NOMINAL IN
SEALING ELEMENT STYLEANGULAR
HOUSING BORE DIAMETER3.940 INCHES NOMINAL IN
MATERIAL DOCUMENT AND CLASSIFICATION9100 FSCM 73680 MFR REF SINGLE MATERIAL RESPONSE SEALING ELEMENT
ACCOMMODATED SHAFT MAXIMUM RATED SPEED3000 FEET PER MINUTE FT
CASE STYLESQUARE
ACCOMMODATED SHAFT DIAMETER3.250 INCHES NOMINAL IN
SURFACE TREATMENTANODIZE CASE
MATERIALRUBBER SYNTHETIC SEALING ELEMENT
OTHER ITEMS IN FSC 5330 — Packing and Gasket Materials
Items in the same Federal Supply class. No interchangeability or substitution relationship is implied.
5330-00-000-0085 5330-00-000-0167 5330-00-000-5275 5330-00-001-1260 5330-00-001-1833 5330-00-001-1844 5330-00-001-1845 5330-00-001-1846
SUBSTITUTES & CROSS-REFERENCES 1
00044Reference document
Same NSN cross-reference
Reference document — Secondary 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 27640-6591?
27640-6591 is a SEAL,PLAIN ENCASED.
What parts can replace 27640-6591?
There is 1 known substitute for 27640-6591: 00044. Substitute compatibility should be verified for your specific system.
What is the NSN for 27640-6591?
27640-6591 is cataloged in the U.S. Government catalog under NSN 5330-00-944-5851. 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.