PartsTable TECHNICAL DATA SHEET
JULY 2026Technical Data Sheet

MILB5423-9Boot,dust and Moisture Seal

Military Specifications Promulgated by Military Departments/agencies Under Authority of Defense Standardization Manual 4120 3-M · NSN 5930-00-402-1021 · FSC 5930 · No Item Name Available
Verified by PartsTable
NSN 5930-00-402-1021 — this item is cataloged by the U.S. Government under National Stock Number 5930-00-402-1021. Primary manufacturer part number: MILB5423-9.
Features
  • Boot,dust and Moisture Seal — FSC 5930
  • Width Across Flats: 0.750 INCHES NOMINAL IN
  • Nominal Thread Size: 0.625 INCHES IN
  • Base Thread Location: INTERNAL
  • Thread Length: 0.175 INCHES NOMINAL IN
  • Thread Series: UNEF
  • Style Designator: THRU-HOLE
  • Mounting Method: THREAD
Applications
  • Fluid containment and leak prevention
  • Pressure boundary maintenance
  • Environmental sealing
  • Applications requiring Rubber Silicone Body construction
General Description

The Boot,dust and Moisture Seal, cataloged under National Stock Number 5930-00-402-1021, is classified within Federal Supply Class 5930 (No Item Name Available) of the Electrical and Electronic Equipment Components group. The primary manufacturer of record is Military Specifications Promulgated by Military Departments/agencies Under Authority of Defense Standardization Manual 4120 3-M. Government technical data includes 15 verified specifications, sourced from the Federal Logistics Information System (FLIS). This item has 3 commercial cross-references from 1 manufacturer, enabling identification through both NSN and commercial part number lookups. 12 verified substitutes exist in the FLIS interchangeability database. Current acquisition status: Active.

Technical Specifications
ParameterValue
NSN5930-00-402-1021
Primary Part NumberMILB5423-9
Item NameBoot,dust and Moisture Seal
FSC / FSG5930 / 59 — No Item Name Available
ManufacturerMilitary Specifications Promulgated by Military Departments/agencies Under Authority of Defense Standardization Manual 4120 3-M
StatusACTIVE
Width Across Flats0.750 INCHES NOMINAL IN
Nominal Thread Size0.625 INCHES IN
Base Thread LocationINTERNAL
Thread Length0.175 INCHES NOMINAL IN
Thread SeriesUNEF
Style DesignatorTHRU-HOLE
Mounting MethodTHREAD
Test Data Document81349-MIL-B-5423 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.).
Mounting Device Quantity1
Opening Inside Diameter0.375 INCHES NOMINAL IN
Base Inside Diameter0.625 INCHES NOMINAL IN
Thread Class2B
FSC Application DataSWITCH,ROTARY
Sealing MethodPACKING
MaterialRUBBER SILICONE BODY
Lifecycle & Compliance
Acquisition StatusACTIVE
HAZMATNo
Verified Substitutes 12
5930-00-140-3241 INTERCHANGEABLE
Boot,dust and Moisture Seal
5930-00-491-8714 INTERCHANGEABLE
Boot,dust and Moisture Seal
5930-00-496-7492N9060X1/4 INTERCHANGEABLE
Boot,dust and Moisture Seal
Apm Hexseal Corp
5930-00-816-6119 INTERCHANGEABLE
Boot,dust and Moisture Seal
5930-00-823-0482 INTERCHANGEABLE
Boot,dust and Moisture Seal
5930-00-823-0573 INTERCHANGEABLE
Boot,dust and Moisture Seal
5930-00-892-9026N9040 1-8 INTERCHANGEABLE
Boot,dust and Moisture Seal
Apm Hexseal Corp
5930-00-904-5904 INTERCHANGEABLE
Boot,dust and Moisture Seal
5930-00-982-9261 INTERCHANGEABLE
Boot,dust and Moisture Seal
5930-00-987-8829 INTERCHANGEABLE
Boot,dust and Moisture Seal
Cross-Reference Index
Part NumberManufacturer
MILB5423-9 Military Specifications Promulgated by Military Departments/agencies Under Authority of Defense Standardization Manual 4120 3-M
M5423/09-11 Military Specifications Promulgated by Military Departments/agencies Under Authority of Defense Standardization Manual 4120 3-M
MIL-DTL-5423/9 Military Specifications Promulgated by Military Departments/agencies Under Authority of Defense Standardization Manual 4120 3-M
Related Parts
5930-00-140-3241INTERCHANGEABLE
BOOT,DUST AND MOISTURE SEAL
5930-00-491-8714INTERCHANGEABLE
BOOT,DUST AND MOISTURE SEAL
5930-00-496-7492INTERCHANGEABLE
BOOT,DUST AND MOISTURE SEAL
N9060X1/4
5930-00-816-6119INTERCHANGEABLE
BOOT,DUST AND MOISTURE SEAL
5930-00-823-0482INTERCHANGEABLE
BOOT,DUST AND MOISTURE SEAL
5930-00-823-0573INTERCHANGEABLE
BOOT,DUST AND MOISTURE SEAL
5930-00-892-9026INTERCHANGEABLE
BOOT,DUST AND MOISTURE SEAL
N9040 1-8
5930-00-904-5904INTERCHANGEABLE
BOOT,DUST AND MOISTURE SEAL
5930-00-982-9261INTERCHANGEABLE
BOOT,DUST AND MOISTURE SEAL
5930-00-987-8829INTERCHANGEABLE
BOOT,DUST AND MOISTURE SEAL
5930-01-154-0858INTERCHANGEABLE
BOOT,DUST AND MOISTURE SEAL
5930-01-412-6919INTERCHANGEABLE
BOOT,DUST AND MOISTURE SEAL

Frequently Asked Questions

What is NSN 5930-00-402-1021?

NSN 5930-00-402-1021 is a Boot,dust and Moisture Seal, manufactured by Military Specifications Promulgated by Military Departments/agencies Under Authority of Defense Standardization Manual 4120 3-M, classified under FSC 5930 (No Item Name Available). Status: active.

What are the part numbers for NSN 5930-00-402-1021?

NSN 5930-00-402-1021 has 3 cross-referenced part numbers: MILB5423-9 (Military Specifications Promulgated by Military Departments/agencies Under Authority of Defense Standardization Manual 4120 3-M), M5423/09-11 (Military Specifications Promulgated by Military Departments/agencies Under Authority of Defense Standardization Manual 4120 3-M), MIL-DTL-5423/9 (Military Specifications Promulgated by Military Departments/agencies Under Authority of Defense Standardization Manual 4120 3-M).

What NSN replaces 5930-00-402-1021?

There are 12 known substitutes for 5930-00-402-1021: 5930-00-140-3241, 5930-00-491-8714, 5930-00-496-7492 and 9 more. Verify interchangeability with system specifications before substitution.

What are the specifications of MILB5423-9?

Key specifications for MILB5423-9: Width Across Flats: 0.750 INCHES NOMINAL IN; Nominal Thread Size: 0.625 INCHES IN; Base Thread Location: INTERNAL; Thread Length: 0.175 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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