PartsTable
Technical Data Sheet

HS4390/4391 — COUPLING HALF,QUICK DISCONNECT

✓ Government record, cited
— · HOSE FITTING
PRODUCT OVERVIEW

HS4390/4391: COUPLING HALF,QUICK DISCONNECT.

The COUPLING HALF,QUICK DISCONNECT is a the manufacturer industrial component. Key specifications include material: STEEL BODY, flow_angle: 90.0 DEGREES, leg_length: 0.484 INCHES NOMINAL IN, seat_angle: 12.0 DEGREES LOCATION NOT OTHERWISE SPECIFIED, thread_class: 3A ALL ENDS A, connection_type: THREADED EXTERNAL TUBE FIRST FLUID END CONNECTION. This part is cataloged in the U.S.

Government catalog under NSN 4730-01-164-6723, 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
HS4390/4391
NSN: 4730-01-164-6723
NIINs: 011646723, 011909759
FSC: 4730 — Hose, Pipe, Tube, Lubrication, and Railing Fittings
CAGE: 02731 — MCDONNELL DOUGLAS HELICOPTER CO INC (USA)
SPECIFICATIONS
materialSTEEL BODY
flow_angle90.0 DEGREES
leg_length0.484 INCHES NOMINAL IN
seat_angle12.0 DEGREES LOCATION NOT OTHERWISE SPECIFIED
thread_class3A ALL ENDS A
connection_typeTHREADED EXTERNAL TUBE FIRST FLUID END CONNECTION
connection_styleFLARELESS ALL ENDS
special_featuresBULKHEAD THREADS ON FLUID END CONNECTION; MATES WITH P/N HS4391-1 (NSN 4730-01-164-6723) TO FORM COUPLING ASSEMBLY HS4390/4391; MAXIMUM OPERATING PRESSURE WHEN COUPLED IS 3000 PSI
style_designatorMALE COUPLING HALF
surface_treatmentPASSIVATE BODY
operating_pressure3000.0 POUNDS PER SQUARE INCH (PSI) MAXIMUM SINGLE RESPONSE LBS
nominal_thread_size0.562 INCHES ALL ENDS IN
NSN4730-01-164-6723
COMPONENT DIAGRAM
HOSE FITTING — THREAD TYPE IS CRITICAL END A: — STRAIGHT END B: — SPECIFICATIONS Thread: — Material: — Pressure: — PN: HS4390/4391 · 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
•
FURNISHED ITEMS AND QUANTITY: 2 NUT
•
CONNECTION STYLE: FLARELESS ALL ENDS
•
CONNECTION TYPE: THREADED EXTERNAL TUBE FIRST FLUID END CONNECTION
•
STYLE DESIGNATOR: MALE COUPLING HALF
•
MATERIAL DOCUMENT AND CLASSIFICATION: QQ-S-763 FED SPEC SINGLE MATERIAL RESPONSE BODY
•
OPERATING PRESSURE: 3000.0 POUNDS PER SQUARE INCH (PSI) MAXIMUM SINGLE RESPONSE LBS
•
NOMINAL THREAD SIZE: 0.562 INCHES ALL ENDS IN
•
SEAT ANGLE: 12.0 DEGREES LOCATION NOT OTHERWISE SPECIFIED
TECHNICAL CHARACTERISTICS
FURNISHED ITEMS AND QUANTITY2 NUT
CONNECTION STYLEFLARELESS ALL ENDS
CONNECTION TYPETHREADED EXTERNAL TUBE FIRST FLUID END CONNECTION
STYLE DESIGNATORMALE COUPLING HALF
MATERIAL DOCUMENT AND CLASSIFICATIONQQ-S-763 FED SPEC SINGLE MATERIAL RESPONSE BODY
OPERATING PRESSURE3000.0 POUNDS PER SQUARE INCH (PSI) MAXIMUM SINGLE RESPONSE LBS
NOMINAL THREAD SIZE0.562 INCHES ALL ENDS IN
SEAT ANGLE12.0 DEGREES LOCATION NOT OTHERWISE SPECIFIED
MAXIMUM OPERATING TEMP275.0 FAHRENHEIT SINGLE RESPONSE DEGF
SURFACE TREATMENTPASSIVATE BODY
SUBSTITUTES & CROSS-REFERENCES 1
HS4391-1Reference document
Same NSN cross-reference
Reference document — Vendor item drawing 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 HS4390/4391?
HS4390/4391 is a COUPLING HALF,QUICK DISCONNECT.
What parts can replace HS4390/4391?
There is 1 known substitute for HS4390/4391: HS4391-1. Substitute compatibility should be verified for your specific system.
What is the NSN for HS4390/4391?
HS4390/4391 is cataloged in the U.S. Government catalog under NSN 4730-01-164-6723. 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.