PartsTable TECHNICAL DATA SHEET
JULY 2026Technical Data Sheet

S721Plug,expansion

Cummins Inc. · NSN 5340-00-050-1571 · FSC 5340 · No Item Name Available
Verified by PartsTable
NSN 5340-00-050-1571 — this item is cataloged by the U.S. Government under National Stock Number 5340-00-050-1571. Primary manufacturer part number: S721.
Features
  • Plug,expansion — FSC 5340
  • Material: COPPER ALLOY
  • Material Thickness: 0.083 INCHES NOMINAL IN
  • Radius: 2.688 INCHES NOMINAL IN
  • Outside Diameter: 1.750 INCHES NOMINAL IN
  • Style Designator: CONCAVE
  • 1 verified cross-reference
  • Primary manufacturer: Cummins Inc.
Applications
  • Applications requiring Copper Alloy construction
General Description

The Plug,expansion, cataloged under National Stock Number 5340-00-050-1571, is classified within Federal Supply Class 5340 (No Item Name Available) of the Hardware and Abrasives group. The primary manufacturer of record is Cummins Inc.. Government technical data includes 5 verified specifications, sourced from the Federal Logistics Information System (FLIS). This item has 1 commercial cross-reference from 1 manufacturer, enabling identification through both NSN and commercial part number lookups. 2 verified substitutes exist in the FLIS interchangeability database. Current acquisition status: Active. Unit of issue: EA.

Technical Specifications
ParameterValue
NSN5340-00-050-1571
Primary Part NumberS721
Item NamePlug,expansion
FSC / FSG5340 / 53 — No Item Name Available
ManufacturerCummins Inc.
StatusACTIVE
MaterialCOPPER ALLOY
Material Thickness0.083 INCHES NOMINAL IN
Radius2.688 INCHES NOMINAL IN
Outside Diameter1.750 INCHES NOMINAL IN
Style DesignatorCONCAVE
Lifecycle & Compliance
Acquisition StatusACTIVE
HAZMATNo
Unit of IssueEA
Verified Substitutes 2
4730-00-277-8266SAE J512 4-4 060202B INTERCHANGEABLE
Elbow,pipe to Tube
Sae International Dba Sae International
5330-00-551-3944 INTERCHANGEABLE
Packing,preformed
Cross-Reference Index
Part NumberManufacturer
S721 PRIMARY Cummins Inc. (USA)
Related Parts
4730-00-277-8266INTERCHANGEABLE
ELBOW,PIPE TO TUBE
SAE J512 4-4 060202B
5330-00-551-3944INTERCHANGEABLE
PACKING,PREFORMED

Frequently Asked Questions

What is NSN 5340-00-050-1571?

NSN 5340-00-050-1571 is a Plug,expansion, manufactured by Cummins Inc., classified under FSC 5340 (No Item Name Available). Status: active.

What are the part numbers for NSN 5340-00-050-1571?

NSN 5340-00-050-1571 has 1 cross-referenced part number: S721 (Cummins Inc.).

What NSN replaces 5340-00-050-1571?

There are 2 known substitutes for 5340-00-050-1571: 4730-00-277-8266, 5330-00-551-3944. Verify interchangeability with system specifications before substitution.

What are the specifications of S721?

Key specifications for S721: Material: COPPER ALLOY; Material Thickness: 0.083 INCHES NOMINAL IN; Radius: 2.688 INCHES NOMINAL IN; Outside Diameter: 1.750 INCHES NOMINAL IN. 5 total characteristics are documented in the Federal Logistics Information System.

Validated with multiple authoritative sources, including Government, OEM, and Certified sources.
PartsTable Design LLC · partstable.com