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MS21906-4C — INJECTOR ASSEMBLY,FUEL

✓ Government record, cited
— · HOSE FITTING
PRODUCT OVERVIEW

MS21906-4C: INJECTOR ASSEMBLY,FUEL.

The INJECTOR ASSEMBLY,FUEL is a the manufacturer industrial component. Key specifications include material: STEEL COMP 304 OR STEEL COMP 316 OVERALL, leg_length: 0.875 INCHES NOMINAL ALL ENDS IN, seat_angle: 12.0 DEGREES ALL ENDS, thread_class: 3A ALL ENDS A, connection_type: THREADED EXTERNAL TUBE ALL ENDS, connection_style: FLARELESS (TUBE) ALL ENDS. This part is cataloged in the U.S.

Government catalog under NSN 4730-00-720-1515, 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
MS21906-4C
NSN: 4730-00-720-1515
FSC: 4730 — Hose, Pipe, Tube, Lubrication, and Railing Fittings
CAGE: 96906 — MILITARY STANDARDS PROMULGATED BY MILITARY DEPARTMENTS UNDER AUTHORITY OF DEFENSE STANDARDIZATION MANUAL 4120 3-M
SPECIFICATIONS
materialSTEEL COMP 304 OR STEEL COMP 316 OVERALL
leg_length0.875 INCHES NOMINAL 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_treatmentPASSIVATE OVERALL
nominal_thread_size0.438 INCHES ALL ENDS IN
maximum_operating_temp-65.0 FAHRENHEIT SECOND RESPONSE DEGF
thread_series_designatorUNIFIED NATIONAL JOINT FINE (UNJF) ALL ENDS
specification/standard_data81343-AS21906 PROFESSIONAL/INDUSTRIAL ASSOCIATION STANDARD
material_document_and_classificationQQ-S-763,CL 304 FED SPEC SINGLE MATERIAL RESPONSE OVERALL
NSN4730-00-720-1515
COMPONENT DIAGRAM
HOSE FITTING — THREAD TYPE IS CRITICAL END A: — STRAIGHT END B: — SPECIFICATIONS Thread: — Material: — Pressure: — PN: MS21906-4C · 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
•
SURFACE TREATMENT DOCUMENT AND CLASSIFICATION: MIL-S-5002 MIL SPEC SINGLE TREATMENT RESPONSE INSIDE
•
CONNECTION STYLE: FLARELESS (TUBE) ALL ENDS
•
CONNECTION TYPE: THREADED EXTERNAL TUBE ALL ENDS
•
MATERIAL DOCUMENT AND CLASSIFICATION: QQ-S-763,CL 304 FED SPEC SINGLE MATERIAL RESPONSE OVERALL
•
NOMINAL OUTSIDE DIAMETER TUBE ACCOMMODATED: 0.250 INCHES ALL ENDS IN
•
LEG LENGTH: 0.875 INCHES NOMINAL ALL ENDS IN
•
NOMINAL THREAD SIZE: 0.438 INCHES ALL ENDS IN
TECHNICAL CHARACTERISTICS
SURFACE TREATMENT DOCUMENT AND CLASSIFICATIONMIL-S-5002 MIL SPEC SINGLE TREATMENT RESPONSE INSIDE
SURFACE TREATMENT DOCUMENT AND CLASSIFICATIONMIL-F-14072,E300,TY2 MIL SPEC SINGLE TREATMENT RESPONSE OUTSIDE
CONNECTION STYLEFLARELESS (TUBE) ALL ENDS
CONNECTION TYPETHREADED EXTERNAL TUBE ALL ENDS
MATERIAL DOCUMENT AND CLASSIFICATIONQQ-S-763,CL 304 FED SPEC SINGLE MATERIAL RESPONSE OVERALL
NOMINAL OUTSIDE DIAMETER TUBE ACCOMMODATED0.250 INCHES ALL ENDS IN
LEG LENGTH0.875 INCHES NOMINAL ALL ENDS IN
NOMINAL THREAD SIZE0.438 INCHES ALL ENDS IN
SEAT ANGLE12.0 DEGREES ALL ENDS
SPECIFICATION/STANDARD DATA81343-AS21906 PROFESSIONAL/INDUSTRIAL ASSOCIATION STANDARD
SUBSTITUTES & CROSS-REFERENCES 5
AS21906Reference document
Same NSN cross-reference
Reference document — Secondary reference
MS21906Reference document
Same NSN cross-reference
Reference document — Secondary reference
AS18280Reference document
Same NSN cross-reference
Reference document — Secondary reference
MS21906J4Reference 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 MS21906-4C?
MS21906-4C is a INJECTOR ASSEMBLY,FUEL.
What parts can replace MS21906-4C?
There are 5 known substitutes for MS21906-4C: AS21906, MS21906, AS18280 and 2 more. Substitute compatibility should be verified for your specific system.
What is the NSN for MS21906-4C?
MS21906-4C is cataloged in the U.S. Government catalog under NSN 4730-00-720-1515. This indicates validated use in U.S. government and defense supply chains.
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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.