PartsTable TECHNICAL DATA SHEET
JULY 2026Technical Data Sheet

FF571Bolt,square Neck

Federal Specifications Promulgated by General Services Administration Washington DC · NSN 5306-00-527-3522 · FSC 5306 · No Item Name Available
Verified by PartsTable
NSN 5306-00-527-3522 — this item is cataloged by the U.S. Government under National Stock Number 5306-00-527-3522. Primary manufacturer part number: FF571.
Features
  • Bolt,square Neck — FSC 5306
  • Thread Quantity Per Inch: 20
  • Neck Length: 0.219 INCHES NOMINAL IN
  • Material Document and Classification: FF-B-571 FED SPEC SINGLE MATERIAL RESPONSE OVERALL
  • Head Diameter: 0.563 INCHES NOMINAL IN
  • Neck Width: 0.250 INCHES NOMINAL IN
  • Nominal Thread Diameter: 0.250 INCHES IN
  • Head Height: 0.125 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 5306-00-527-3522, is classified within Federal Supply Class 5306 (No Item Name Available) of the Hardware and Abrasives group. The primary manufacturer of record is Federal Specifications Promulgated by General Services Administration Washington DC. Government technical data includes 17 verified specifications, sourced from the Federal Logistics Information System (FLIS). This item has 3 commercial cross-references from 3 manufacturers, enabling identification through both NSN and commercial part number lookups. 4 verified substitutes exist in the FLIS interchangeability database. Current acquisition status: Active.

Technical Specifications
ParameterValue
NSN5306-00-527-3522
Primary Part NumberFF571
Item NameBolt,square Neck
FSC / FSG5306 / 53 — No Item Name Available
ManufacturerFederal Specifications Promulgated by General Services Administration Washington DC
StatusACTIVE
Thread Quantity Per Inch20
Neck Length0.219 INCHES NOMINAL IN
Material Document and ClassificationFF-B-571 FED SPEC SINGLE MATERIAL RESPONSE OVERALL
Head Diameter0.563 INCHES NOMINAL IN
Neck Width0.250 INCHES NOMINAL IN
Nominal Thread Diameter0.250 INCHES IN
Head Height0.125 INCHES NOMINAL IN
Thread Class2A A
Fastener Length4.750 INCHES NOMINAL IN
Head StyleBUTTON
Nondefinitive Spec/std DataC2 TYPE AND C CLASS
Thread DirectionRIGHT-HAND
Thread Series DesignatorUNIFIED NATIONAL COARSE (UNC)
MaterialSTEEL OVERALL
Minimum Tensile Strength48000 POUNDS PER SQUARE INCH LBS
Features ProvidedSQUARE NUT
Thread Length0.875 INCHES MINIMUM IN
Lifecycle & Compliance
Acquisition StatusACTIVE
HAZMATNo
Verified Substitutes 4
5133-00-266-9470 INTERCHANGEABLE
Drill,twist
5342-00-523-319670446 INTERCHANGEABLE
Bracket,engine Moun
Textron Lycoming Inc Williamsport Plant
3110-01-375-755970446 INTERCHANGEABLE
Bearing,ball,thrust
Ingersoll-Rand Co Material Handling Div
5305-01-496-431870446 INTERCHANGEABLE
Screw,cap,socket Head
Cummins Inc
Cross-Reference Index
Part NumberManufacturer
FF571 Federal Specifications Promulgated by General Services Administration Washington DC (USA)
70-4-46 Department of the Air Force (USA)
70-4-46 Air Force Standard
Related Parts
5133-00-266-9470INTERCHANGEABLE
DRILL,TWIST
5342-00-523-3196INTERCHANGEABLE
BRACKET,ENGINE MOUN
70446
3110-01-375-7559INTERCHANGEABLE
BEARING,BALL,THRUST
70446
5305-01-496-4318INTERCHANGEABLE
SCREW,CAP,SOCKET HEAD
70446

Frequently Asked Questions

What is NSN 5306-00-527-3522?

NSN 5306-00-527-3522 is a Bolt,square Neck, manufactured by Federal Specifications Promulgated by General Services Administration Washington DC, classified under FSC 5306 (No Item Name Available). Status: active.

What are the part numbers for NSN 5306-00-527-3522?

NSN 5306-00-527-3522 has 3 cross-referenced part numbers: FF571 (Federal Specifications Promulgated by General Services Administration Washington DC), 70-4-46 (Department of the Air Force), 70-4-46 (Air Force Standard).

What NSN replaces 5306-00-527-3522?

There are 4 known substitutes for 5306-00-527-3522: 5133-00-266-9470, 5342-00-523-3196, 3110-01-375-7559 and 1 more. Verify interchangeability with system specifications before substitution.

What are the specifications of FF571?

Key specifications for FF571: Thread Quantity Per Inch: 20; Neck Length: 0.219 INCHES NOMINAL IN; Material Document and Classification: FF-B-571 FED SPEC SINGLE MATERIAL RESPONSE OVERALL; Head Diameter: 0.563 INCHES NOMINAL IN. 17 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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