PartsTable TECHNICAL DATA SHEET
JULY 2026Technical Data Sheet

H66716-0403Screw,cap,socket Head

Kearfott Corporation Div Guidance and Navigation Division · NSN 5305-00-638-1278 · FSC 5305 · No Item Name Available
Verified by PartsTable
NSN 5305-00-638-1278 — this item is cataloged by the U.S. Government under National Stock Number 5305-00-638-1278. Primary manufacturer part number: H66716-0403.
Features
  • Screw,cap,socket Head — FSC 5305
  • Hardness Rating: 80.0 ROCKWELL B MINIMUM OVERALL
  • Thread Class: 3A A
  • Material Document and Classification: 66 FED STD ALL MATERIAL RESPONSES OVERALL
  • Minimum Yield Strength: 30000 POUNDS PER SQUARE INCH LBS
  • Internal Drive Style: HEXAGON
  • Head Diameter: 0.176 INCHES MINIMUM AND 0.183 INCHES MAXIMUM IN
  • Surface Treatment Document and Classification: QQ-P-35 FED SPEC SINGLE TREATMENT RESPONSE OVERALL
Applications
  • Structural fastening and assembly
  • Equipment mounting
  • Panel and housing attachment
  • Applications requiring Steel Comp 302 or Steel Comp 303 or Steel Comp 304 or Steel Comp 305 or Steel Comp 316 Overall construction
General Description

The Screw,cap,socket Head, cataloged under National Stock Number 5305-00-638-1278, is classified within Federal Supply Class 5305 (No Item Name Available) of the Hardware and Abrasives group. The primary manufacturer of record is Kearfott Corporation Div Guidance and Navigation Division. Government technical data includes 20 verified specifications, sourced from the Federal Logistics Information System (FLIS). This item has 4 commercial cross-references from 4 manufacturers, enabling identification through both NSN and commercial part number lookups. 1 verified substitute exists in the FLIS interchangeability database. Current acquisition status: Cancelled.

Technical Specifications
ParameterValue
NSN5305-00-638-1278
Primary Part NumberH66716-0403
Item NameScrew,cap,socket Head
FSC / FSG5305 / 53 — No Item Name Available
ManufacturerKearfott Corporation Div Guidance and Navigation Division
StatusCANCELLED
Hardness Rating80.0 ROCKWELL B MINIMUM OVERALL
Thread Class3A A
Material Document and Classification66 FED STD ALL MATERIAL RESPONSES OVERALL
Minimum Yield Strength30000 POUNDS PER SQUARE INCH LBS
Internal Drive StyleHEXAGON
Head Diameter0.176 INCHES MINIMUM AND 0.183 INCHES MAXIMUM IN
Surface Treatment Document and ClassificationQQ-P-35 FED SPEC SINGLE TREATMENT RESPONSE OVERALL
Thread Series DesignatorUNIFIED NATIONAL COARSE (UNC)
Surface TreatmentPASSIVATE OVERALL
MaterialSTEEL COMP 302 OR STEEL COMP 303 OR STEEL COMP 304 OR STEEL COMP 305 OR STEEL COMP 316 OVERALL
Nominal Thread Diameter0.112 INCHES IN
Nondefinitive Spec/std Data1 TYPE
Head Height0.108 INCHES MINIMUM AND 0.112 INCHES MAXIMUM IN
Head StyleFLAT CHAMFER
Minimum Tensile Strength80000 POUNDS PER SQUARE INCH LBS
Width Across Flats0.078 INCHES NOMINAL IN
Thread Length0.169 INCHES MINIMUM IN
Thread DirectionRIGHT-HAND
Fastener Length0.188 INCHES NOMINAL IN
Thread Quantity Per Inch40
Lifecycle & Compliance
Acquisition StatusCANCELLED
HAZMATNo
Verified Substitutes 1
5995-00-733-8658XH2077 INTERCHANGEABLE
Cable Assembly,magneto Ground
Heale Manufacturing Co Llc
Cross-Reference Index
Part NumberManufacturer
H66716-0403 PRIMARY Kearfott Corporation Div Guidance and Navigation Division (USA)
FFS86TYPE1 Federal Specifications Promulgated by General Services Administration Washington DC (USA)
1054640 Navair and Navsea Managed Original Design Activity Dwg Not Material/parts Supplier (USA)
NAS608C440-3 National Aerospace Standards Committee Aerospace Industries Association of America Inc Not for Rfq or Solicitation Use (USA)
Related Parts
5995-00-733-8658INTERCHANGEABLE
CABLE ASSEMBLY,MAGNETO GROUND
XH2077

Frequently Asked Questions

What is NSN 5305-00-638-1278?

NSN 5305-00-638-1278 is a Screw,cap,socket Head, manufactured by Kearfott Corporation Div Guidance and Navigation Division, classified under FSC 5305 (No Item Name Available). Status: cancelled.

What are the part numbers for NSN 5305-00-638-1278?

NSN 5305-00-638-1278 has 4 cross-referenced part numbers: H66716-0403 (Kearfott Corporation Div Guidance and Navigation Division), FFS86TYPE1 (Federal Specifications Promulgated by General Services Administration Washington DC), 1054640 (Navair and Navsea Managed Original Design Activity Dwg Not Material/parts Supplier), NAS608C440-3 (National Aerospace Standards Committee Aerospace Industries Association of America Inc Not for Rfq or Solicitation Use).

What NSN replaces 5305-00-638-1278?

There is 1 known substitute for 5305-00-638-1278: 5995-00-733-8658. Verify interchangeability with system specifications before substitution.

What are the specifications of H66716-0403?

Key specifications for H66716-0403: Hardness Rating: 80.0 ROCKWELL B MINIMUM OVERALL; Thread Class: 3A A; Material Document and Classification: 66 FED STD ALL MATERIAL RESPONSES OVERALL; Minimum Yield Strength: 30000 POUNDS PER SQUARE INCH LBS. 20 total characteristics are documented in the Federal Logistics Information System.

Is NSN 5305-00-638-1278 still in active supply?

NSN 5305-00-638-1278 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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