PartsTable TECHNICAL DATA SHEET
JULY 2026Technical Data Sheet

81564Screw,externally Relieved Body

Telemechanics Inc · NSN 5305-00-639-7127 · FSC 5305 · No Item Name Available
Verified by PartsTable
NSN 5305-00-639-7127 — this item is cataloged by the U.S. Government under National Stock Number 5305-00-639-7127. Primary manufacturer part number: 81564.
Features
  • Screw,externally Relieved Body — FSC 5305
  • Internal Drive Style: SLOT
  • Thread Series Designator: UNF
  • First Diameter From Head: 0.093 INCHES NOMINAL IN
  • Head Diameter: 0.312 INCHES NOMINAL IN
  • Thread Class: 3A A
  • Distance From Largest Bearing Surface of Head to End of First Diameter: 0.025 INCHES NOMINAL IN
  • Head Style: FILLISTER
Applications
  • Structural fastening and assembly
  • Equipment mounting
  • Panel and housing attachment
  • Applications requiring Steel Overall construction
General Description

The Screw,externally Relieved Body, cataloged under National Stock Number 5305-00-639-7127, is classified within Federal Supply Class 5305 (No Item Name Available) of the Hardware and Abrasives group. The primary manufacturer of record is Telemechanics Inc. Government technical data includes 18 verified specifications, sourced from the Federal Logistics Information System (FLIS). This item has 2 commercial cross-references from 2 manufacturers, enabling identification through both NSN and commercial part number lookups. 2 verified substitutes exist in the FLIS interchangeability database. Current acquisition status: Cancelled.

Technical Specifications
ParameterValue
NSN5305-00-639-7127
Primary Part Number81564
Item NameScrew,externally Relieved Body
FSC / FSG5305 / 53 — No Item Name Available
ManufacturerTelemechanics Inc
StatusCANCELLED
Internal Drive StyleSLOT
Thread Series DesignatorUNF
First Diameter From Head0.093 INCHES NOMINAL IN
Head Diameter0.312 INCHES NOMINAL IN
Thread Class3A A
Distance From Largest Bearing Surface of Head to End of First Diameter0.025 INCHES NOMINAL IN
Head StyleFILLISTER
Thread Quantity Per Inch40
Distance From Largest Bearing Surface of Head to End of Second Diameter0.406 INCHES NOMINAL IN
Surface TreatmentNICKEL OVERALL
Externally Relieved Body Diameter Quantity2
Fastener Length0.406 INCHES NOMINAL IN
MaterialSTEEL OVERALL
Thread Length0.328 INCHES MINIMUM IN
Head Height0.620 INCHES NOMINAL IN
Nominal Thread Diameter0.138 INCHES IN
Second Diameter From Head0.138 INCHES NOMINAL IN
Thread DirectionRIGHT-HAND
Lifecycle & Compliance
Acquisition StatusCANCELLED
HAZMATNo
Verified Substitutes 2
5340-00-912-212781564 INTERCHANGEABLE
Cover,access
Raytheon Company Dba Raytheon Co
4820-01-199-7892 INTERCHANGEABLE
Disk,valve
Cross-Reference Index
Part NumberManufacturer
81564 PRIMARY Telemechanics Inc (USA)
81564 At and T Corp (USA)
Related Parts
5340-00-912-2127INTERCHANGEABLE
COVER,ACCESS
81564
4820-01-199-7892INTERCHANGEABLE
DISK,VALVE

Frequently Asked Questions

What is NSN 5305-00-639-7127?

NSN 5305-00-639-7127 is a Screw,externally Relieved Body, manufactured by Telemechanics Inc, classified under FSC 5305 (No Item Name Available). Status: cancelled.

What are the part numbers for NSN 5305-00-639-7127?

NSN 5305-00-639-7127 has 2 cross-referenced part numbers: 81564 (Telemechanics Inc), 81564 (At and T Corp).

What NSN replaces 5305-00-639-7127?

There are 2 known substitutes for 5305-00-639-7127: 5340-00-912-2127, 4820-01-199-7892. Verify interchangeability with system specifications before substitution.

What are the specifications of 81564?

Key specifications for 81564: Internal Drive Style: SLOT; Thread Series Designator: UNF; First Diameter From Head: 0.093 INCHES NOMINAL IN; Head Diameter: 0.312 INCHES NOMINAL IN. 18 total characteristics are documented in the Federal Logistics Information System.

Is NSN 5305-00-639-7127 still in active supply?

NSN 5305-00-639-7127 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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