PartsTable TECHNICAL DATA SHEET
JULY 2026Technical Data Sheet

MS21937W4HPacking Nut

Sae International Dba Sae International · NSN 4730-00-684-0564 · FSC 4730 · No Item Name Available
Verified by PartsTable
NSN 4730-00-684-0564 — this item is cataloged by the U.S. Government under National Stock Number 4730-00-684-0564. Primary manufacturer part number: MS21937W4H.
Features
  • Packing Nut — FSC 4730
  • Thread Size: 7/16IN-20 IN
  • Largest Inside Diameter: 0.875 INCHES NOMINAL IN
  • Screw Thread Series Designator: UNIFIED NATIONAL JOINT FINE (UNJF)
  • Screw Thread Location: INTERNAL
  • Major Unthreaded Outside Diameter: 1.000 INCHES NOMINAL IN
  • Width Across Flats: 1.000 INCHES NOMINAL IN
  • Length to Shoulder: 0.344 INCHES NOMINAL IN
Applications
  • Structural fastening and assembly
  • Equipment mounting
  • Panel and housing attachment
  • Applications requiring Aluminum Alloy 2014 construction
General Description

The Packing Nut, cataloged under National Stock Number 4730-00-684-0564, 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 Sae International Dba Sae International. Government technical data includes 17 verified specifications, sourced from the Federal Logistics Information System (FLIS). This item has 17 commercial cross-references from 9 manufacturers, enabling identification through both NSN and commercial part number lookups. 4 verified substitutes exist in the FLIS interchangeability database. Current acquisition status: Cancelled.

Technical Specifications
ParameterValue
NSN4730-00-684-0564
Primary Part NumberMS21937W4H
Item NamePacking Nut
FSC / FSG4730 / 47 — No Item Name Available
ManufacturerSae International Dba Sae International
StatusCANCELLED
Thread Size7/16IN-20 IN
Largest Inside Diameter0.875 INCHES NOMINAL IN
Screw Thread Series DesignatorUNIFIED NATIONAL JOINT FINE (UNJF)
Screw Thread LocationINTERNAL
Major Unthreaded Outside Diameter1.000 INCHES NOMINAL IN
Width Across Flats1.000 INCHES NOMINAL IN
Length to Shoulder0.344 INCHES NOMINAL IN
MaterialALUMINUM ALLOY 2014
Surface TreatmentANODIZE
Style DesignatorHEXAGON, INTERNAL THREAD, SHOULDERED
Surface Treatment Document and ClassificationMIL-A-8625,TYPE 2,CLASS 1 MIL SPEC SINGLE TREATMENT RESPONSE
Test Data Document81349-MIL-F-18280C SPECIFICATION (INCLUDES ENGINEERING TYPE BULLETINS, BROCHURES,ETC., THAT REFLECT SPECIFICATION TYPE DATA IN SPECIFICATION FORMAT; EXCLUDES COMMERCIAL CATALOGS, INDUSTRY DIRECTORIES, AND SIMILAR TRADE PUBLICATIONS, REFLECTING GENERAL TYPE DATA ON CERTAIN ENVIRONMENTAL AND PERFORMANCE REQUIREMENTS AND TEST CONDITIONS THAT ARE SHOWN AS "TYPICAL", "AVERAGE", "NOMINAL", ETC.).
Unthreaded Portion Length0.156 INCHES NOMINAL IN
Thread DirectionRIGHT-HAND
Thread Class3B
Thread Length0.344 INCHES NOMINAL IN
Casehardening IndicatorNOT CASEHARDENED
Lifecycle & Compliance
Acquisition StatusCANCELLED
HAZMATNo
Verified Substitutes 4
4730-00-222-1912 INTERCHANGEABLE
Nut,tube Coupling
4730-00-433-2974MS21937-5H INTERCHANGEABLE
Packing Nut
Precision Form Rivet Inc
4730-00-541-2173MS21937W8H INTERCHANGEABLE
Packing Nut
Sae International Dba Sae International
4730-00-821-0189MS21937-4L INTERCHANGEABLE
Packing Nut
Sae International Dba Sae International
Cross-Reference Index
Part NumberManufacturer
AS18280 Society of Automotive Engineers Inc (USA)
MS21937-4H Society of Automotive Engineers Inc (USA)
MS21937-4HC Military Standards Promulgated by Military Departments Under Authority of Defense Standardization Manual 4120 3-M
MS21937W4H Society of Automotive Engineers Inc (USA)
SAE-AS18280 Sae International Dba Sae International (USA)
MS21937-4H Parker Hannifin Corp Stratoflex Div Aircraft Fittings Opn (USA)
MS21937W4H PRIMARY Sae International Dba Sae International (USA)
MS21937-4H Military Standards Promulgated by Military Departments Under Authority of Defense Standardization Manual 4120 3-M
MS21937-4H Faber Enterprises, Inc. Div Faber Enterprise Inc (USA)
AS18280 Sae International Dba Sae International (USA)
MS21937-4H Parker-Hannifin Corporation Dba Pneutronics Div Corporate Headquarters (USA)
MS21937-4H Eaton Aeroquip Llc Dba Jackson North 1 Div Fluid and Electrical Distribution (USA)
AS21937 Society of Automotive Engineers Inc (USA)
AS21937 Sae International Dba Sae International (USA)
MS21937-4H Dana Corp Weatherhead Div (USA)
105-01584 Dana Corp Weatherhead Div (USA)
MS21937-4H Globe Aerospace Inc (USA)
Related Parts
4730-00-222-1912INTERCHANGEABLE
NUT,TUBE COUPLING
4730-00-433-2974INTERCHANGEABLE
PACKING NUT
MS21937-5H
4730-00-541-2173INTERCHANGEABLE
PACKING NUT
MS21937W8H
4730-00-821-0189INTERCHANGEABLE
PACKING NUT
MS21937-4L

Frequently Asked Questions

What is NSN 4730-00-684-0564?

NSN 4730-00-684-0564 is a Packing Nut, manufactured by Sae International Dba Sae International, classified under FSC 4730 (No Item Name Available). Status: cancelled.

What are the part numbers for NSN 4730-00-684-0564?

NSN 4730-00-684-0564 has 17 cross-referenced part numbers: AS18280 (Society of Automotive Engineers Inc), MS21937-4H (Society of Automotive Engineers Inc), MS21937-4HC (Military Standards Promulgated by Military Departments Under Authority of Defense Standardization Manual 4120 3-M), MS21937W4H (Society of Automotive Engineers Inc), SAE-AS18280 (Sae International Dba Sae International) and 12 more.

What NSN replaces 4730-00-684-0564?

There are 4 known substitutes for 4730-00-684-0564: 4730-00-222-1912, 4730-00-433-2974, 4730-00-541-2173 and 1 more. Verify interchangeability with system specifications before substitution.

What are the specifications of MS21937W4H?

Key specifications for MS21937W4H: Thread Size: 7/16IN-20 IN; Overall Length: 0.500 INCHES NOMINAL IN; Largest Inside Diameter: 0.875 INCHES NOMINAL IN; Screw Thread Series Designator: UNIFIED NATIONAL JOINT FINE (UNJF). 18 total characteristics are documented in the Federal Logistics Information System.

Is NSN 4730-00-684-0564 still in active supply?

NSN 4730-00-684-0564 is currently cancelled. Check with the Defense Logistics Agency for current availability and authorized substitutes.

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