PartsTable TECHNICAL DATA SHEET
JULY 2026Technical Data Sheet

126657Bolt,square Neck

U S Army Tank Automotive Command Amsta-Im-Mm · NSN 5306-00-012-6657 · FSC 5306 · No Item Name Available
Verified by PartsTable
NSN 5306-00-012-6657 — this item is cataloged by the U.S. Government under National Stock Number 5306-00-012-6657. Primary manufacturer part number: 126657.
Features
  • Bolt,square Neck — FSC 5306
  • Head Diameter: 0.688 INCHES NOMINAL IN
  • Neck Width: 0.307 INCHES MINIMUM AND 0.324 INCHES MAXIMUM IN
  • Material: STEEL OVERALL
  • Thread Series Designator: UNIFIED NATIONAL COARSE (UNC)
  • Thread Class: 2A A
  • Neck Length: 0.156 INCHES MINIMUM AND 0.187 INCHES MAXIMUM IN
  • Fastener Length: 2.750 INCHES NOMINAL IN
Applications
  • Structural fastening and assembly
  • Equipment mounting
  • Panel and housing attachment
  • Applications requiring Steel Overall construction
General Description

The Bolt,square Neck, cataloged under National Stock Number 5306-00-012-6657, is classified within Federal Supply Class 5306 (No Item Name Available) of the Hardware and Abrasives group. The primary manufacturer of record is U S Army Tank Automotive Command Amsta-Im-Mm. Government technical data includes 16 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. 5 verified substitutes exist in the FLIS interchangeability database. Current acquisition status: Cancelled.

Technical Specifications
ParameterValue
NSN5306-00-012-6657
Primary Part Number126657
Item NameBolt,square Neck
FSC / FSG5306 / 53 — No Item Name Available
ManufacturerU S Army Tank Automotive Command Amsta-Im-Mm
StatusCANCELLED
Head Diameter0.688 INCHES NOMINAL IN
Neck Width0.307 INCHES MINIMUM AND 0.324 INCHES MAXIMUM IN
MaterialSTEEL OVERALL
Thread Series DesignatorUNIFIED NATIONAL COARSE (UNC)
Thread Class2A A
Neck Length0.156 INCHES MINIMUM AND 0.187 INCHES MAXIMUM IN
Fastener Length2.750 INCHES NOMINAL IN
Thread Length0.875 INCHES MINIMUM IN
Minimum Tensile Strength55000 POUNDS PER SQUARE INCH LBS
Thread DirectionRIGHT-HAND
Head StyleBUTTON
Hardness Rating95.0 ROCKWELL B MAXIMUM OVERALL
Thread Quantity Per Inch18
Head Height0.156 INCHES NOMINAL IN
Nominal Thread Diameter0.312 INCHES IN
Surface TreatmentCADMIUM OR ZINC OVERALL
Lifecycle & Compliance
Acquisition StatusCANCELLED
HAZMATNo
Verified Substitutes 5
4320-00-308-8020126657 INTERCHANGEABLE
Valve Plate,hydraulic Motor-Pump
Eaton Aerospace, Llc Dba Jackson South
5355-00-322-0268 INTERCHANGEABLE
Knob
5985-00-479-3431126657 INTERCHANGEABLE
Drive,antenna
L3harris Technologies, Inc Div Space & Airborne Systems
2040-01-462-0367126657 INTERCHANGEABLE
Fender,marine
Jered Llc
1650-01-708-0479126657-908 INTERCHANGEABLE
Actuator,electro-Pneumatic
Honeywell International Inc. Dba Honeywell International Div Aerospace - Tempe (west Warner Road)
Cross-Reference Index
Part NumberManufacturer
126657 PRIMARY U S Army Tank Automotive Command Amsta-Im-Mm (USA)
Related Parts
4320-00-308-8020INTERCHANGEABLE
VALVE PLATE,HYDRAULIC MOTOR-PUMP
126657
5355-00-322-0268INTERCHANGEABLE
KNOB
5985-00-479-3431INTERCHANGEABLE
DRIVE,ANTENNA
126657
2040-01-462-0367INTERCHANGEABLE
FENDER,MARINE
126657
1650-01-708-0479INTERCHANGEABLE
ACTUATOR,ELECTRO-PNEUMATIC
126657-908

Frequently Asked Questions

What is NSN 5306-00-012-6657?

NSN 5306-00-012-6657 is a Bolt,square Neck, manufactured by U S Army Tank Automotive Command Amsta-Im-Mm, classified under FSC 5306 (No Item Name Available). Status: cancelled.

What are the part numbers for NSN 5306-00-012-6657?

NSN 5306-00-012-6657 has 1 cross-referenced part number: 126657 (U S Army Tank Automotive Command Amsta-Im-Mm).

What NSN replaces 5306-00-012-6657?

There are 5 known substitutes for 5306-00-012-6657: 4320-00-308-8020, 5355-00-322-0268, 5985-00-479-3431 and 2 more. Verify interchangeability with system specifications before substitution.

What are the specifications of 126657?

Key specifications for 126657: Head Diameter: 0.688 INCHES NOMINAL IN; Neck Width: 0.307 INCHES MINIMUM AND 0.324 INCHES MAXIMUM IN; Material: STEEL OVERALL; Thread Series Designator: UNIFIED NATIONAL COARSE (UNC). 16 total characteristics are documented in the Federal Logistics Information System.

Is NSN 5306-00-012-6657 still in active supply?

NSN 5306-00-012-6657 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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