PartsTable TECHNICAL DATA SHEET
JULY 2026Technical Data Sheet

AN818-32DNut,tube Coupling

Aeronautical Standards Group Dept of Navy and Air Force · NSN 4730-00-278-8561 · FSC 4730 · No Item Name Available
Verified by PartsTable
NSN 4730-00-278-8561 — this item is cataloged by the U.S. Government under National Stock Number 4730-00-278-8561. Primary manufacturer part number: AN818-32D.
Features
  • Nut,tube Coupling — FSC 4730
  • Length to Shoulder: 1.462 INCHES NOMINAL IN
  • Nut Height: 1.734 INCHES NOMINAL IN
  • Surface Treatment: ANODIZE OVERALL
  • Material: ALUMINUM ALLOY OVERALL
  • Nominal Thread Size: 2.500 INCHES IN
  • Smallest Inside Diameter: 2.167 INCHES MINIMUM AND 2.170 INCHES MAXIMUM IN
  • Thread Series: UN
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 4730-00-278-8561, 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 Aeronautical Standards Group Dept of Navy and Air Force. Government technical data includes 13 verified specifications, sourced from the Federal Logistics Information System (FLIS). This item has 8 commercial cross-references from 6 manufacturers, 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
NSN4730-00-278-8561
Primary Part NumberAN818-32D
Item NameNut,tube Coupling
FSC / FSG4730 / 47 — No Item Name Available
ManufacturerAeronautical Standards Group Dept of Navy and Air Force
StatusACTIVE
Length to Shoulder1.462 INCHES NOMINAL IN
Nut Height1.734 INCHES NOMINAL IN
Surface TreatmentANODIZE OVERALL
MaterialALUMINUM ALLOY OVERALL
Nominal Thread Size2.500 INCHES IN
Smallest Inside Diameter2.167 INCHES MINIMUM AND 2.170 INCHES MAXIMUM IN
Thread SeriesUN
Nominal Tube Outside Diameter2.000 INCHES IN
Nut StyleTUBE COUPLING
Thread Quantity Per Inch12
Thread Class3B
Width Across Flats2.855 INCHES MINIMUM AND 2.895 INCHES MAXIMUM IN
Thread DirectionRIGHT-HAND
Lifecycle & Compliance
Acquisition StatusACTIVE
HAZMATNo
Verified Substitutes 3
4730-00-273-8561 INTERCHANGEABLE
Adapter,straight,pipe to Tube
4730-00-278-4574SAE J512 6-4 060102BA INTERCHANGEABLE
Adapter,straight,pipe to Tube
Sae International Dba Sae International
5935-01-243-8139 INTERCHANGEABLE
Connector,receptacle,electrical
Cross-Reference Index
Part NumberManufacturer
AN818-32D Aeronautical Standards Group Dept of Navy and Air Force (USA)
290-32D Eaton Aeroquip Llc Dba Jackson North 1 Div Fluid and Electrical Distribution (USA)
SAE-AS4841 Sae International Dba Sae International (USA)
720337-32 Lockheed Martin Corporation Div Rms - Mitchel Field (USA)
AS4841 Sae International Dba Sae International (USA)
731857-132 Lockheed Martin Corporation Div Rms - Mitchel Field (USA)
290-32D Satair A/s (DNK)
CA1208 Clark Equipment Co (USA)
Related Parts
4730-00-273-8561INTERCHANGEABLE
ADAPTER,STRAIGHT,PIPE TO TUBE
4730-00-278-4574INTERCHANGEABLE
ADAPTER,STRAIGHT,PIPE TO TUBE
SAE J512 6-4 060102BA
5935-01-243-8139INTERCHANGEABLE
CONNECTOR,RECEPTACLE,ELECTRICAL

Frequently Asked Questions

What is NSN 4730-00-278-8561?

NSN 4730-00-278-8561 is a Nut,tube Coupling, manufactured by Aeronautical Standards Group Dept of Navy and Air Force, classified under FSC 4730 (No Item Name Available). Status: active.

What are the part numbers for NSN 4730-00-278-8561?

NSN 4730-00-278-8561 has 8 cross-referenced part numbers: AN818-32D (Aeronautical Standards Group Dept of Navy and Air Force), 290-32D (Eaton Aeroquip Llc Dba Jackson North 1 Div Fluid and Electrical Distribution), SAE-AS4841 (Sae International Dba Sae International), 720337-32 (Lockheed Martin Corporation Div Rms - Mitchel Field), AS4841 (Sae International Dba Sae International) and 3 more.

What NSN replaces 4730-00-278-8561?

There are 3 known substitutes for 4730-00-278-8561: 4730-00-273-8561, 4730-00-278-4574, 5935-01-243-8139. Verify interchangeability with system specifications before substitution.

What are the specifications of AN818-32D?

Key specifications for AN818-32D: Length to Shoulder: 1.462 INCHES NOMINAL IN; Nut Height: 1.734 INCHES NOMINAL IN; Surface Treatment: ANODIZE OVERALL; Material: ALUMINUM ALLOY OVERALL. 13 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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