PartsTable
Technical Data Sheet
Download PDF

3178205 — NUT,UNION

✓ Government record, cited
— · HOSE FITTING
PRODUCT OVERVIEW

3178205: NUT,UNION.

The NUT,UNION is a the manufacturer industrial component. Key specifications include material: STEEL CORROSION RESISTING OVERALL, thread_class: 2A ALL ENDS A, connection_type: THREADED EXTERNAL TUBE ALL ENDS, connection_style: PLAIN (TUBE) ALL ENDS, special_features: O-RING GROOVE 0.563 IN. OD,WIDTH 0.104 IN.,DEPTH 0.052 IN.

BOTH ENDS IN, style_designator: LONG W/ OFFSET WRENCHING FACILITY. This part is cataloged in the U.S. Government catalog under NSN 4730-01-057-8783, 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
3178205
NSN: 4730-01-057-8783
NIINs: 010578783, 010884804, 011212846
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 CORROSION RESISTING OVERALL
thread_class2A ALL ENDS A
connection_typeTHREADED EXTERNAL TUBE ALL ENDS
connection_stylePLAIN (TUBE) ALL ENDS
special_featuresO-RING GROOVE 0.563 IN. OD,WIDTH 0.104 IN.,DEPTH 0.052 IN. BOTH ENDS IN
style_designatorLONG W/ OFFSET WRENCHING FACILITY
surface_treatmentPASSIVATE OVERALL
nominal_thread_size0.688 INCHES ALL ENDS IN
nominal_overall_length1.780 INCHES IN
thread_quantity_per_inch16 ALL ENDS
thread_series_designatorUN ALL ENDS
material_document_and_classificationQQ-S-763,CL 304,TY 2 FED SPEC SINGLE MATERIAL RESPONSE OVERALL
NSN4730-01-057-8783
COMPONENT DIAGRAM
HOSE FITTING — THREAD TYPE IS CRITICAL END A: — STRAIGHT END B: — SPECIFICATIONS Thread: — Material: — Pressure: — PN: 3178205 · 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
•
NUT STYLE: HEXAGON
TECHNICAL CHARACTERISTICS
NUT STYLEHEXAGON
SUBSTITUTES & CROSS-REFERENCES 1
H850N6Same NSN cross-reference
Same NSN cross-reference
Also cataloged under this NSN
LIFECYCLE
NSN statusActive· U.S. Government catalog
Acquisition advice: Insurance item — stocked against contingency demandNo demilitarization required
Ready to buy 3178205?
Compare prices from verified sellers on eBay
Buy on eBay →
As an eBay Partner, PartsTable may earn a commission. Your price is not affected.
FREQUENTLY ASKED QUESTIONS
What is 3178205?
3178205 is a NUT,UNION.
What parts can replace 3178205?
There is 1 known substitute for 3178205: H850N6. Substitute compatibility should be verified for your specific system.
What is the NSN for 3178205?
3178205 is cataloged in the U.S. Government catalog under NSN 4730-01-057-8783. This indicates validated use in U.S. government and defense supply chains.
Community Feedback
Leave a Comment
Comments are reviewed before appearing. You will receive an email to verify before your comment appears.

Request a Quote — 3178205

✓ 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.