PartsTable TECHNICAL DATA SHEET
JULY 2026Technical Data Sheet

81839Coupling,boss

Hydro-Aire Aerospace Corp · NSN 4730-00-925-4727 · FSC 4730 · No Item Name Available
Verified by PartsTable
NSN 4730-00-925-4727 — this item is cataloged by the U.S. Government under National Stock Number 4730-00-925-4727. Primary manufacturer part number: 81839.
Features
  • Coupling,boss — FSC 4730
  • Thread Class: 3B FIRST END
  • Connection Style: EXTERNAL SEAT FOR GASKET SEAL (BOSS) SECOND END
  • Surface Treatment: ANODIZE OVERALL
  • Style Designator: RIGID, THREADED INTERNAL AND EXTERNAL
  • Connection Style: GASKET SEAL (BOSS) FIRST END
  • Media for Which Designed: FLUID SINGLE RESPONSE
  • Connection Type: THREADED EXTERNAL BOSS SECOND END
Applications
  • Applications requiring Aluminum Alloy Overall construction
General Description

The Coupling,boss, cataloged under National Stock Number 4730-00-925-4727, is classified within Federal Supply Class 4730 (No Item Name Available) of the Pipe, Tubing, Hose, and Fittings group. The primary manufacturer of record is Hydro-Aire Aerospace Corp. Government technical data includes 15 verified specifications, sourced from the Federal Logistics Information System (FLIS). This item has 1 commercial cross-reference from 1 manufacturer, enabling identification through both NSN and commercial part number lookups. 3 verified substitutes exist in the FLIS interchangeability database. Current acquisition status: Active.

Technical Specifications
ParameterValue
NSN4730-00-925-4727
Primary Part Number81839
Item NameCoupling,boss
FSC / FSG4730 / 47 — No Item Name Available
ManufacturerHydro-Aire Aerospace Corp
StatusACTIVE
Thread Class3B FIRST END
Connection StyleEXTERNAL SEAT FOR GASKET SEAL (BOSS) SECOND END
Surface TreatmentANODIZE OVERALL
Style DesignatorRIGID, THREADED INTERNAL AND EXTERNAL
Connection StyleGASKET SEAL (BOSS) FIRST END
Media for Which DesignedFLUID SINGLE RESPONSE
Connection TypeTHREADED EXTERNAL BOSS SECOND END
Thread Series DesignatorUNF ALL ENDS
Material Document and ClassificationQQ-A-268,COND T FED SPEC SINGLE MATERIAL RESPONSE OVERALL
Surface Treatment Document and ClassificationMIL-A-8625,TYPE 1 MIL SPEC SINGLE TREATMENT RESPONSE OVERALL
Nominal Thread Size0.750 INCHES ALL ENDS IN
Nominal Overall Length1.380 INCHES IN
Thread Class3A SECOND END A
MaterialALUMINUM ALLOY OVERALL
Connection TypeTHREADED INTERNAL BOSS FIRST END
Lifecycle & Compliance
Acquisition StatusACTIVE
HAZMATNo
Verified Substitutes 3
2920-00-659-691890-2054 INTERCHANGEABLE
Cap,ignition Distribution
Prestolite Electric Inc
5133-00-838-5371 INTERCHANGEABLE
Drill,twist
2990-01-103-9333A-1839 INTERCHANGEABLE
Clutch,housing
Crown Coachworks Inc Div Crown Coachworks Auto Body & Paint
Cross-Reference Index
Part NumberManufacturer
81839 PRIMARY Hydro-Aire Aerospace Corp (USA)
Related Parts
2920-00-659-6918INTERCHANGEABLE
CAP,IGNITION DISTRIBUTION
90-2054
5133-00-838-5371INTERCHANGEABLE
DRILL,TWIST
2990-01-103-9333INTERCHANGEABLE
CLUTCH,HOUSING
A-1839

Frequently Asked Questions

What is NSN 4730-00-925-4727?

NSN 4730-00-925-4727 is a Coupling,boss, manufactured by Hydro-Aire Aerospace Corp, classified under FSC 4730 (No Item Name Available). Status: active.

What are the part numbers for NSN 4730-00-925-4727?

NSN 4730-00-925-4727 has 1 cross-referenced part number: 81839 (Hydro-Aire Aerospace Corp).

What NSN replaces 4730-00-925-4727?

There are 3 known substitutes for 4730-00-925-4727: 2920-00-659-6918, 5133-00-838-5371, 2990-01-103-9333. Verify interchangeability with system specifications before substitution.

What are the specifications of 81839?

Key specifications for 81839: Thread Class: 3B FIRST END; Connection Style: EXTERNAL SEAT FOR GASKET SEAL (BOSS) SECOND END; Special Features: FEMALE END 1.000 IN. OD HEX IN; Surface Treatment: ANODIZE OVERALL. 16 total characteristics are documented in the Federal Logistics Information System.

Validated with multiple authoritative sources, including Government, OEM, and Certified sources.
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