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MS21904W12 — INJECTOR ASSEMBLY,FUEL

✓ Government record, cited
— · HOSE FITTING
PRODUCT OVERVIEW

MS21904W12: INJECTOR ASSEMBLY,FUEL.

The INJECTOR ASSEMBLY,FUEL is a the manufacturer industrial component. Key specifications include material: ALUMINUM ALLOY OVERALL, flow_angle: 90.0 DEGREES, leg_length: 1.562 INCHES MINIMUM AND 1.609 INCHES MAXIMUM ALL ENDS IN, seat_angle: 12.0 DEGREES ALL ENDS, thread_class: 3A ALL ENDS A, connection_type: THREADED EXTERNAL TUBE ALL ENDS. This part is cataloged in the U.S.

Government catalog under NSN 4730-00-640-5093, 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
MS21904W12
NSN: 4730-00-640-5093
FSC: 4730 — Hose, Pipe, Tube, Lubrication, and Railing Fittings
CAGE: 0U583 — SAE INTERNATIONAL DBA SAE INTERNATIONAL (USA)
SPECIFICATIONS
materialALUMINUM ALLOY OVERALL
flow_angle90.0 DEGREES
leg_length1.562 INCHES MINIMUM AND 1.609 INCHES MAXIMUM ALL ENDS IN
seat_angle12.0 DEGREES ALL ENDS
thread_class3A ALL ENDS A
connection_typeTHREADED EXTERNAL TUBE ALL ENDS
connection_styleFLARELESS (TUBE) ALL ENDS
surface_treatmentANODIZE OVERALL
nominal_thread_size1.062 INCHES ALL ENDS IN
end_item_identificationUSED ON SIKORSKY MODEL CH-54A AND CH-54B CARGO TRANSPORT HELICOPTERS A
thread_quantity_per_inch12 ALL ENDS
thread_series_designatorUNIFIED NATIONAL JOINT (UNJ) ALL ENDS
NSN4730-00-640-5093
COMPONENT DIAGRAM
HOSE FITTING — THREAD TYPE IS CRITICAL END A: — STRAIGHT END B: — SPECIFICATIONS Thread: — Material: — Pressure: — PN: MS21904W12 · 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
•
FLOW ANGLE: 90.0 DEGREES
•
SURFACE TREATMENT DOCUMENT AND CLASSIFICATION: MIL-A-8625 MIL SPEC SINGLE TREATMENT RESPONSE OUTSIDE
•
CONNECTION STYLE: FLARELESS (TUBE) ALL ENDS
•
CONNECTION TYPE: THREADED EXTERNAL TUBE ALL ENDS
•
NOMINAL OUTSIDE DIAMETER TUBE ACCOMMODATED: 0.750 INCHES ALL ENDS IN
•
LEG LENGTH: 1.562 INCHES MINIMUM AND 1.609 INCHES MAXIMUM ALL ENDS IN
•
NOMINAL THREAD SIZE: 1.062 INCHES ALL ENDS IN
TECHNICAL CHARACTERISTICS
FLOW ANGLE90.0 DEGREES
SURFACE TREATMENT DOCUMENT AND CLASSIFICATIONMIL-A-8625 MIL SPEC SINGLE TREATMENT RESPONSE OUTSIDE
SURFACE TREATMENT DOCUMENT AND CLASSIFICATIONMIL-A-8625 MIL SPEC SINGLE TREATMENT RESPONSE INSIDE
CONNECTION STYLEFLARELESS (TUBE) ALL ENDS
CONNECTION TYPETHREADED EXTERNAL TUBE ALL ENDS
NOMINAL OUTSIDE DIAMETER TUBE ACCOMMODATED0.750 INCHES ALL ENDS IN
LEG LENGTH1.562 INCHES MINIMUM AND 1.609 INCHES MAXIMUM ALL ENDS IN
NOMINAL THREAD SIZE1.062 INCHES ALL ENDS IN
SEAT ANGLE12.0 DEGREES ALL ENDS
SPECIFICATION/STANDARD DATA81343-AS21904 GOVERNMENT STANDARD
SUBSTITUTES & CROSS-REFERENCES 4
AS18280Reference document
Same NSN cross-reference
Reference document — Secondary reference
MS21904D12Reference document
Same NSN cross-reference
Reference document — Secondary reference
AS21904Reference document
Same NSN cross-reference
Reference document — Secondary reference
SAE-AS18280Reference document
Same NSN cross-reference
Reference document — Design control — primary 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 MS21904W12?
MS21904W12 is a INJECTOR ASSEMBLY,FUEL.
What parts can replace MS21904W12?
There are 4 known substitutes for MS21904W12: AS18280, MS21904D12, AS21904 and 1 more. Substitute compatibility should be verified for your specific system.
What is the NSN for MS21904W12?
MS21904W12 is cataloged in the U.S. Government catalog under NSN 4730-00-640-5093. 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.