PartsTable TECHNICAL DATA SHEET
JULY 2026Technical Data Sheet

MS21937-5HPacking Nut

Precision Form Rivet Inc · NSN 4730-00-433-2974 · FSC 4730 · No Item Name Available
Verified by PartsTable
NSN 4730-00-433-2974 — this item is cataloged by the U.S. Government under National Stock Number 4730-00-433-2974. Primary manufacturer part number: MS21937-5H.
Features
  • Packing Nut — FSC 4730
  • Unthreaded Portion Length: 0.156 INCHES NOMINAL IN
  • Style Designator: HEXAGON, INTERNAL THREAD, SHOULDERED
  • Smallest Inside Diameter: 0.500 INCHES NOMINAL IN
  • Length to Shoulder: 0.344 INCHES NOMINAL IN
  • Width Across Flats: 1.000 INCHES NOMINAL IN
  • Major Unthreaded Outside Diameter: 1.000 INCHES NOMINAL IN
  • Screw Thread Location: INTERNAL
Applications
  • Structural fastening and assembly
  • Equipment mounting
  • Panel and housing attachment
  • Applications requiring Aluminum Alloy 2024 construction
General Description

The Packing Nut, cataloged under National Stock Number 4730-00-433-2974, 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 Precision Form Rivet Inc. Government technical data includes 15 verified specifications, sourced from the Federal Logistics Information System (FLIS). This item has 12 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
NSN4730-00-433-2974
Primary Part NumberMS21937-5H
Item NamePacking Nut
FSC / FSG4730 / 47 — No Item Name Available
ManufacturerPrecision Form Rivet Inc
StatusACTIVE
Unthreaded Portion Length0.156 INCHES NOMINAL IN
Style DesignatorHEXAGON, INTERNAL THREAD, SHOULDERED
Smallest Inside Diameter0.500 INCHES NOMINAL IN
Length to Shoulder0.344 INCHES NOMINAL IN
Width Across Flats1.000 INCHES NOMINAL IN
Major Unthreaded Outside Diameter1.000 INCHES NOMINAL IN
Screw Thread LocationINTERNAL
MaterialALUMINUM ALLOY 2024
Thread Size1/2IN-20 IN
Casehardening IndicatorNOT CASEHARDENED
Thread DirectionRIGHT-HAND
Thread Length0.344 INCHES NOMINAL IN
Largest Inside Diameter0.875 INCHES NOMINAL IN
Screw Thread Series DesignatorUNF
Thread Class3B
Lifecycle & Compliance
Acquisition StatusACTIVE
HAZMATNo
Verified Substitutes 3
4730-00-541-2173MS21937W8H INTERCHANGEABLE
Packing Nut
Sae International Dba Sae International
4730-00-684-0564MS21937W4H 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
MS21937-5H PRIMARY Precision Form Rivet Inc (USA)
MS21937-5H Designed Metal Connections Inc Dba Permaswage Usa Div Permaswage, a Pcc Company (USA)
MS21937-5H PRIMARY Sae International Dba Sae International (USA)
AS21937 Sae International Dba Sae International (USA)
MS21937-5H PRIMARY Eaton Aeroquip Llc Dba Jackson North 1 Div Fluid and Electrical Distribution (USA)
MS21937-5H Military Standards Promulgated by Military Departments Under Authority of Defense Standardization Manual 4120 3-M
SAE-AS18280 Sae International Dba Sae International (USA)
MS21927-5H Sae International Dba Sae International (USA)
AS18280 Sae International Dba Sae International (USA)
AS18280 Society of Automotive Engineers Inc (USA)
AS21937 Society of Automotive Engineers Inc (USA)
MS21927-5H Society of Automotive Engineers Inc (USA)
Related Parts
4730-00-541-2173INTERCHANGEABLE
PACKING NUT
MS21937W8H
4730-00-684-0564INTERCHANGEABLE
PACKING NUT
MS21937W4H
4730-00-821-0189INTERCHANGEABLE
PACKING NUT
MS21937-4L

Frequently Asked Questions

What is NSN 4730-00-433-2974?

NSN 4730-00-433-2974 is a Packing Nut, manufactured by Precision Form Rivet Inc, classified under FSC 4730 (No Item Name Available). Status: active.

What are the part numbers for NSN 4730-00-433-2974?

NSN 4730-00-433-2974 has 12 cross-referenced part numbers: MS21937-5H (Precision Form Rivet Inc), MS21937-5H (Designed Metal Connections Inc Dba Permaswage Usa Div Permaswage, a Pcc Company), MS21937-5H (Sae International Dba Sae International), AS21937 (Sae International Dba Sae International), MS21937-5H (Eaton Aeroquip Llc Dba Jackson North 1 Div Fluid and Electrical Distribution) and 7 more.

What NSN replaces 4730-00-433-2974?

There are 3 known substitutes for 4730-00-433-2974: 4730-00-541-2173, 4730-00-684-0564, 4730-00-821-0189. Verify interchangeability with system specifications before substitution.

What are the specifications of MS21937-5H?

Key specifications for MS21937-5H: Unthreaded Portion Length: 0.156 INCHES NOMINAL IN; Style Designator: HEXAGON, INTERNAL THREAD, SHOULDERED; Smallest Inside Diameter: 0.500 INCHES NOMINAL IN; Length to Shoulder: 0.344 INCHES NOMINAL IN. 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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