PartsTable TECHNICAL DATA SHEET
JULY 2026Technical Data Sheet

3F3728Ring,retaining

Caterpillar Inc Div Caterpillar Defense · NSN 5325-00-281-6648 · FSC 5325 · No Item Name Available
Verified by PartsTable
NSN 5325-00-281-6648 — this item is cataloged by the U.S. Government under National Stock Number 5325-00-281-6648. Primary manufacturer part number: 3F3728.
Features
  • Ring,retaining — FSC 5325
  • Major Thickness: 0.125 INCHES NOMINAL IN
  • Inside Diameter: 3.500 INCHES NOMINAL IN
  • Cross-Sectional Shape Style: RECTANGULAR
  • Material: STEEL
  • Casehardening Indicator: NOT CASEHARDENED
  • End Style: VERTEX OUTSIDE PERIPHERY
  • Ring Style: STRAIGHT GAP
Applications
  • Applications requiring Steel construction
General Description

The Ring,retaining, cataloged under National Stock Number 5325-00-281-6648, is classified within Federal Supply Class 5325 (No Item Name Available) of the Hardware and Abrasives group. The primary manufacturer of record is Caterpillar Inc Div Caterpillar Defense. Government technical data includes 9 verified specifications, sourced from the Federal Logistics Information System (FLIS). This item has 6 commercial cross-references from 4 manufacturers, enabling identification through both NSN and commercial part number lookups. 6 verified substitutes exist in the FLIS interchangeability database. Current acquisition status: Cancelled.

Technical Specifications
ParameterValue
NSN5325-00-281-6648
Primary Part Number3F3728
Item NameRing,retaining
FSC / FSG5325 / 53 — No Item Name Available
ManufacturerCaterpillar Inc Div Caterpillar Defense
StatusCANCELLED
Major Thickness0.125 INCHES NOMINAL IN
Inside Diameter3.500 INCHES NOMINAL IN
Cross-Sectional Shape StyleRECTANGULAR
MaterialSTEEL
Casehardening IndicatorNOT CASEHARDENED
End StyleVERTEX OUTSIDE PERIPHERY
Ring StyleSTRAIGHT GAP
Outside Diameter3.875 INCHES NOMINAL IN
Usage DesignEXTERNAL
Lifecycle & Compliance
Acquisition StatusCANCELLED
HAZMATNo
Verified Substitutes 6
5130-00-293-2410 INTERCHANGEABLE
Brush,wire,rotary End
3895-00-352-3954 INTERCHANGEABLE
Pump Assembly,dual
7025-00-403-7470 INTERCHANGEABLE
Keytop,keyboard
6685-00-526-7748 INTERCHANGEABLE
Thermometer,self-Indicating
5998-01-068-265021418 INTERCHANGEABLE
Circuit Card Assembly
Drs Signal Solutions, Inc.
5310-01-362-8577A2044 INTERCHANGEABLE
Nut Elastic
Hartzell Propeller Llc
Cross-Reference Index
Part NumberManufacturer
A2044 Twin Disc, Incorporated Dba Twin Disc Mid-Atlantic (USA)
3F3728 PRIMARY Caterpillar Inc Div Caterpillar Defense (USA)
21418 PRIMARY Wausau Equipment Company Llc Dba Schmidt Engineering & Equipment Inc Div Wausau Equipment Llc (USA)
A2622L PRIMARY Twin Disc, Incorporated Dba Twin Disc Mid-Atlantic (USA)
21418 Klauer Manufacturing Company (USA)
5B2405 PRIMARY Caterpillar Inc Div Caterpillar Defense (USA)
Related Parts
5130-00-293-2410INTERCHANGEABLE
BRUSH,WIRE,ROTARY END
3895-00-352-3954INTERCHANGEABLE
PUMP ASSEMBLY,DUAL
7025-00-403-7470INTERCHANGEABLE
KEYTOP,KEYBOARD
6685-00-526-7748INTERCHANGEABLE
THERMOMETER,SELF-INDICATING
5998-01-068-2650INTERCHANGEABLE
CIRCUIT CARD ASSEMBLY
21418
5310-01-362-8577INTERCHANGEABLE
NUT ELASTIC
A2044

Frequently Asked Questions

What is NSN 5325-00-281-6648?

NSN 5325-00-281-6648 is a Ring,retaining, manufactured by Caterpillar Inc Div Caterpillar Defense, classified under FSC 5325 (No Item Name Available). Status: cancelled.

What are the part numbers for NSN 5325-00-281-6648?

NSN 5325-00-281-6648 has 6 cross-referenced part numbers: A2044 (Twin Disc, Incorporated Dba Twin Disc Mid-Atlantic), 3F3728 (Caterpillar Inc Div Caterpillar Defense), 21418 (Wausau Equipment Company Llc Dba Schmidt Engineering & Equipment Inc Div Wausau Equipment Llc), A2622L (Twin Disc, Incorporated Dba Twin Disc Mid-Atlantic), 21418 (Klauer Manufacturing Company) and 1 more.

What NSN replaces 5325-00-281-6648?

There are 6 known substitutes for 5325-00-281-6648: 5130-00-293-2410, 3895-00-352-3954, 7025-00-403-7470 and 3 more. Verify interchangeability with system specifications before substitution.

What are the specifications of 3F3728?

Key specifications for 3F3728: Major Thickness: 0.125 INCHES NOMINAL IN; Inside Diameter: 3.500 INCHES NOMINAL IN; Cross-Sectional Shape Style: RECTANGULAR; Material: STEEL. 9 total characteristics are documented in the Federal Logistics Information System.

Is NSN 5325-00-281-6648 still in active supply?

NSN 5325-00-281-6648 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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