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3258421-1 — EXPANSION JOINT,PIPE

✓ Government record, cited
— · HOSE FITTING
PRODUCT OVERVIEW

3258421-1: EXPANSION JOINT,PIPE.

The EXPANSION JOINT,PIPE is a the manufacturer industrial component. Key specifications include material: STEEL FLANGE, overall_length: 5.125 INCHES NOMINAL IN, special_features: WEAPON SYSTEM ESSENTIAL, surface_treatment: CADMIUM FLANGE, end_connection_type: FLANGED, bolt_circle_diameter: 6.000 INCHES NOMINAL IN. This part is cataloged in the U.S.

Government catalog under NSN 4730-01-274-0807, 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
3258421-1
NSN: 4730-01-274-0807
FSC: 4730 — Hose, Pipe, Tube, Lubrication, and Railing Fittings
CAGE: 10001 — NAVAIR AND NAVSEA MANAGED ORIGINAL DESIGN ACTIVITY DWG NOT MATERIAL/PARTS SUPPLIER (USA)
SPECIFICATIONS
materialSTEEL FLANGE
overall_length5.125 INCHES NOMINAL IN
special_featuresWEAPON SYSTEM ESSENTIAL
surface_treatmentCADMIUM FLANGE
bolt_hole_quantity4
end_connection_typeFLANGED
bolt_circle_diameter6.000 INCHES NOMINAL IN
flange_outside_diameter7.500 INCHES NOMINAL IN
working_pressure_rating225.0 POUNDS PER SQUARE INCH (PSI) NOMINAL LBS
nominal_pipe_size_designation3.000 INCHES IN
criticality_code_justificationFEAT
screw_thread_series_designatorUNIFIED NATIONAL COARSE (UNC)
NSN4730-01-274-0807
COMPONENT DIAGRAM
HOSE FITTING — THREAD TYPE IS CRITICAL END A: — STRAIGHT END B: — SPECIFICATIONS Thread: — Material: — Pressure: — PN: 3258421-1 · OEM ⚠ VERIFY BEFORE ORDERING NPT ≠ BSPT — tapered threads look identical but are NOT interchangeable. Wrong thread = leak. JIC (37°) ≠ AN (37°) ≠ SAE 45° — flare angles must match exactly. Measure thread pitch with gauge — visual identification is unreliable ✓ BROKER TIP Always use thread sealant (PTFE tape or pipe compound) on tapered threads (NPT/BSPT). JIC/AN flare fittings seal metal-to-metal — never use tape on flare connections PARTSTABLE TECHNICAL DRAWING — NOT TO SCALE
KEY FEATURES
•
NOMINAL PIPE SIZE DESIGNATION: 3.000 INCHES IN
•
END CONNECTION TYPE: FLANGED
•
CRITICALITY CODE JUSTIFICATION: FEAT
•
WORKING PRESSURE RATING: 225.0 POUNDS PER SQUARE INCH (PSI) NOMINAL LBS
•
BOLT HOLE QUANTITY: 4
•
BOLT CIRCLE DIAMETER: 6.000 INCHES NOMINAL IN
TECHNICAL CHARACTERISTICS
NOMINAL PIPE SIZE DESIGNATION3.000 INCHES IN
END CONNECTION TYPEFLANGED
CRITICALITY CODE JUSTIFICATIONFEAT
OVERALL LENGTH5.125 INCHES NOMINAL IN
WORKING PRESSURE RATING225.0 POUNDS PER SQUARE INCH (PSI) NOMINAL LBS
BOLT HOLE QUANTITY4
BOLT CIRCLE DIAMETER6.000 INCHES NOMINAL IN
SPECIAL FEATURESWEAPON SYSTEM ESSENTIAL
SCREW THREAD SERIES DESIGNATORUNIFIED NATIONAL COARSE (UNC)
SURFACE TREATMENTCADMIUM FLANGE
OTHER ITEMS IN FSC 4730 — Hose, Pipe, Tube, Lubrication, and Railing Fittings
Items in the same Federal Supply class. No interchangeability or substitution relationship is implied.
4730-00-000-1895 4730-00-000-4289 4730-00-000-4445 4730-00-000-8373 4730-00-000-8897 4730-00-001-0007 4730-00-001-0008
SUBSTITUTES & CROSS-REFERENCES 2
800-USA-1Same NSN cross-reference
Same NSN cross-reference
Also cataloged under this NSN
METRASPHERE 3IN-OUNReference document
Same NSN cross-reference
Reference document — Secondary reference
LIFECYCLE
NSN statusActive· U.S. Government catalog
Shelf-life managedAcquisition advice: Terminal item — stock exhausted; no further procurementNo demilitarization required
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FREQUENTLY ASKED QUESTIONS
What is 3258421-1?
3258421-1 is a EXPANSION JOINT,PIPE.
What parts can replace 3258421-1?
There are 2 known substitutes for 3258421-1: 800-USA-1, METRASPHERE 3IN-OUN. Substitute compatibility should be verified for your specific system.
What is the NSN for 3258421-1?
3258421-1 is cataloged in the U.S. Government catalog under NSN 4730-01-274-0807. 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.