PartsTable TECHNICAL DATA SHEET
JULY 2026Technical Data Sheet

181DNut,tube Coupling

Imperial · NSN 4730-00-278-8819 · FSC 4730 · No Item Name Available
Verified by PartsTable
NSN 4730-00-278-8819 — this item is cataloged by the U.S. Government under National Stock Number 4730-00-278-8819. Primary manufacturer part number: 181D.
Features
  • Nut,tube Coupling — FSC 4730
  • Nut Height: 0.781 INCHES NOMINAL IN
  • Thread Series: UNF
  • Fabrication Method: MACHINED
  • Thread Quantity Per Inch: 16
  • Material: COPPER ALLOY OVERALL
  • Smallest Inside Diameter: 0.503 INCHES NOMINAL IN
  • Nominal Thread Size: 0.687 INCHES IN
Applications
  • Structural fastening and assembly
  • Equipment mounting
  • Panel and housing attachment
  • Fluid conveyance
  • Hydraulic system plumbing
General Description

The Nut,tube Coupling, cataloged under National Stock Number 4730-00-278-8819, 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 Imperial. Government technical data includes 12 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. 2 verified substitutes exist in the FLIS interchangeability database. Current acquisition status: Active.

Technical Specifications
ParameterValue
NSN4730-00-278-8819
Primary Part Number181D
Item NameNut,tube Coupling
FSC / FSG4730 / 47 — No Item Name Available
ManufacturerImperial
StatusACTIVE
Nut Height0.781 INCHES NOMINAL IN
Thread SeriesUNF
Fabrication MethodMACHINED
Thread Quantity Per Inch16
MaterialCOPPER ALLOY OVERALL
Smallest Inside Diameter0.503 INCHES NOMINAL IN
Nominal Thread Size0.687 INCHES IN
Width Across Flats0.688 INCHES NOMINAL IN
Nut StyleTUBE COUPLING
Nominal Tube Outside Diameter0.500 INCHES IN
Thread Class2A A
Thread DirectionRIGHT-HAND
Lifecycle & Compliance
Acquisition StatusACTIVE
HAZMATNo
Verified Substitutes 2
4730-00-142-15936100X4 INTERCHANGEABLE
Inverted Nut,tube Coupling
Danfoss Power Solutions II, Llc
4730-00-288-8011106-10005 INTERCHANGEABLE
Inverted Nut,tube Coupling
Danfoss Power Solutions II, Llc
Cross-Reference Index
Part NumberManufacturer
181D Imperial (USA)
Related Parts
4730-00-142-1593INTERCHANGEABLE
INVERTED NUT,TUBE COUPLING
6100X4
4730-00-288-8011INTERCHANGEABLE
INVERTED NUT,TUBE COUPLING
106-10005

Frequently Asked Questions

What is NSN 4730-00-278-8819?

NSN 4730-00-278-8819 is a Nut,tube Coupling, manufactured by Imperial, classified under FSC 4730 (No Item Name Available). Status: active.

What are the part numbers for NSN 4730-00-278-8819?

NSN 4730-00-278-8819 has 1 cross-referenced part number: 181D (Imperial).

What NSN replaces 4730-00-278-8819?

There are 2 known substitutes for 4730-00-278-8819: 4730-00-142-1593, 4730-00-288-8011. Verify interchangeability with system specifications before substitution.

What are the specifications of 181D?

Key specifications for 181D: Nut Height: 0.781 INCHES NOMINAL IN; Thread Series: UNF; Fabrication Method: MACHINED; Thread Quantity Per Inch: 16. 12 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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