PartsTable TECHNICAL DATA SHEET
JULY 2026Technical Data Sheet

3-66391Washer,flat

The Boeing Company Div Defense · NSN 5310-00-033-7112 · FSC 5310 · No Item Name Available
Verified by PartsTable
NSN 5310-00-033-7112 — this item is cataloged by the U.S. Government under National Stock Number 5310-00-033-7112. Primary manufacturer part number: 3-66391.
Features
  • Washer,flat — FSC 5310
  • Width Across Flats: 0.600 INCHES NOMINAL IN
  • Thickness: 0.064 INCHES NOMINAL IN
  • Material: ALUMINUM ALLOY OVERALL
  • Overall Diameter: 1.000 INCHES NOMINAL IN
  • Cross-Sectional Shape Style: RECTANGULAR
  • Surface Treatment: ANODIZE OVERALL
  • Center Hole Shape Style: ROUND
Applications
  • Structural fastening and assembly
  • Equipment mounting
  • Panel and housing attachment
  • Applications requiring Aluminum Alloy Overall construction
General Description

The Washer,flat, cataloged under National Stock Number 5310-00-033-7112, is classified within Federal Supply Class 5310 (No Item Name Available) of the Hardware and Abrasives group. The primary manufacturer of record is The Boeing Company Div Defense. Government technical data includes 11 verified specifications, sourced from the Federal Logistics Information System (FLIS). This item has 2 commercial cross-references from 2 manufacturers, enabling identification through both NSN and commercial part number lookups. 5 verified substitutes exist in the FLIS interchangeability database. Current acquisition status: Active.

Technical Specifications
ParameterValue
NSN5310-00-033-7112
Primary Part Number3-66391
Item NameWasher,flat
FSC / FSG5310 / 53 — No Item Name Available
ManufacturerThe Boeing Company Div Defense
StatusACTIVE
Width Across Flats0.600 INCHES NOMINAL IN
Thickness0.064 INCHES NOMINAL IN
MaterialALUMINUM ALLOY OVERALL
Overall Diameter1.000 INCHES NOMINAL IN
Cross-Sectional Shape StyleRECTANGULAR
Surface TreatmentANODIZE OVERALL
Center Hole Shape StyleROUND
Surface Treatment Document and ClassificationMIL-A-8625 MIL SPEC SINGLE TREATMENT RESPONSE OVERALL
Material Document and ClassificationQQ-A-287 FED SPEC SINGLE MATERIAL RESPONSE OVERALL
Peripheral Shape StyleROUND W/FLATS
Hole Diameter0.260 INCHES MINIMUM AND 0.280 INCHES MAXIMUM IN
Lifecycle & Compliance
Acquisition StatusACTIVE
HAZMATNo
Verified Substitutes 5
5331-00-248-38482601730-22 INTERCHANGEABLE
O-Ring
Naval Air Systems Command Managed Original Design Activity Not Material/parts Supplier
4730-00-278-575700520 INTERCHANGEABLE
Cup,oil,lubricating
Gits Mfg Co Inc
4730-00-707-3068 INTERCHANGEABLE
Cup,oil,lubricating
5331-01-147-074600520H INTERCHANGEABLE
O-Ring
Griswold Industries Dba Cla-Val Co
4730-01-283-381100520 INTERCHANGEABLE
Cup,oil,lubricating
Gits Bros Mfg Co
Cross-Reference Index
Part NumberManufacturer
3-66391 PRIMARY The Boeing Company Div Defense (USA)
00520 Defense Logistics Agency Dba Defense Supply Center Philadelphia (USA)
Related Parts
5331-00-248-3848INTERCHANGEABLE
O-RING
2601730-22
4730-00-278-5757INTERCHANGEABLE
CUP,OIL,LUBRICATING
00520
4730-00-707-3068INTERCHANGEABLE
CUP,OIL,LUBRICATING
5331-01-147-0746INTERCHANGEABLE
O-RING
00520H
4730-01-283-3811INTERCHANGEABLE
CUP,OIL,LUBRICATING
00520

Frequently Asked Questions

What is NSN 5310-00-033-7112?

NSN 5310-00-033-7112 is a Washer,flat, manufactured by The Boeing Company Div Defense, classified under FSC 5310 (No Item Name Available). Status: active.

What are the part numbers for NSN 5310-00-033-7112?

NSN 5310-00-033-7112 has 2 cross-referenced part numbers: 3-66391 (The Boeing Company Div Defense), 00520 (Defense Logistics Agency Dba Defense Supply Center Philadelphia).

What NSN replaces 5310-00-033-7112?

There are 5 known substitutes for 5310-00-033-7112: 5331-00-248-3848, 4730-00-278-5757, 4730-00-707-3068 and 2 more. Verify interchangeability with system specifications before substitution.

What are the specifications of 3-66391?

Key specifications for 3-66391: Width Across Flats: 0.600 INCHES NOMINAL IN; Thickness: 0.064 INCHES NOMINAL IN; Material: ALUMINUM ALLOY OVERALL; Overall Diameter: 1.000 INCHES NOMINAL IN. 11 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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