PartsTable TECHNICAL DATA SHEET
JULY 2026Technical Data Sheet

50FK420Nut,self-Locking,slotted,hexagon

Sps Technologies, Llc Dba PB Fasteners · NSN 5310-00-550-9449 · FSC 5310 · No Item Name Available
Verified by PartsTable
NSN 5310-00-550-9449 — this item is cataloged by the U.S. Government under National Stock Number 5310-00-550-9449. Primary manufacturer part number: 50FK420.
Features
  • Nut,self-Locking,slotted,hexagon — FSC 5310
  • Thread Direction: RIGHT-HAND
  • Locking Feature: PREVAILING TORQUE ALL METAL DESIGN
  • Bearing Surface Type: WASHER FACED
  • Nominal Thread Size: 0.250 INCHES IN
  • Material: STEEL CORROSION RESISTING OVERALL
  • Surface Treatment: PASSIVATE OVERALL
  • Nut Style: SLOTTED, HEXAGON
Applications
  • Structural fastening and assembly
  • Equipment mounting
  • Panel and housing attachment
  • Applications requiring Steel Corrosion Resisting Overall construction
General Description

The Nut,self-Locking,slotted,hexagon, cataloged under National Stock Number 5310-00-550-9449, is classified within Federal Supply Class 5310 (No Item Name Available) of the Hardware and Abrasives group. The primary manufacturer of record is Sps Technologies, Llc Dba PB Fasteners. Government technical data includes 13 verified specifications, sourced from the Federal Logistics Information System (FLIS). This item has 5 commercial cross-references from 5 manufacturers, enabling identification through both NSN and commercial part number lookups. 11 verified substitutes exist in the FLIS interchangeability database. Current acquisition status: Active.

Technical Specifications
ParameterValue
NSN5310-00-550-9449
Primary Part Number50FK420
Item NameNut,self-Locking,slotted,hexagon
FSC / FSG5310 / 53 — No Item Name Available
ManufacturerSps Technologies, Llc Dba PB Fasteners
StatusACTIVE
Thread DirectionRIGHT-HAND
Locking FeaturePREVAILING TORQUE ALL METAL DESIGN
Bearing Surface TypeWASHER FACED
Nominal Thread Size0.250 INCHES IN
MaterialSTEEL CORROSION RESISTING OVERALL
Surface TreatmentPASSIVATE OVERALL
Nut StyleSLOTTED, HEXAGON
Thread Class2B
Thread SeriesUNIFIED NATIONAL COARSE (UNC)
Nut Height0.189 INCHES MINIMUM AND 0.209 INCHES MAXIMUM IN
Width Across Flats0.430 INCHES MINIMUM AND 0.439 INCHES MAXIMUM IN
Thread Quantity Per Inch20
Temp Rating800.0 FAHRENHEIT NOMINAL DEGF
Lifecycle & Compliance
Acquisition StatusACTIVE
HAZMATNo
Verified Substitutes 11
5310-00-004-1490 INTERCHANGEABLE
Nut,self-Locking,hexagon
5310-00-050-9012 INTERCHANGEABLE
Nut,plain,knurled
5905-00-190-8885 INTERCHANGEABLE
Resistor,fixed,composition
6505-00-300-0571 INTERCHANGEABLE
Sodium Borate
5330-01-016-57783574 INTERCHANGEABLE
Packing Material
A W Chesterton Co Div Sealing Device Division
5345-01-050-991808834180307 INTERCHANGEABLE
Abrasive,cartridge Roll
Saint-Gobain Abrasives Inc
5905-01-096-36753574 INTERCHANGEABLE
Resistor
Crown Audio, Inc. Dba Crown International
5310-01-142-364150FK-420 INTERCHANGEABLE
Nut,self-Locking,hexagon
Sps Technologies, Llc Dba PB Fasteners
5305-01-344-631780307 INTERCHANGEABLE
Screw,cap,socket Head
Fastenal Company Div Bind
3040-01-447-41213574 INTERCHANGEABLE
Shaft,straight
Coffin Turbo Pump Inc
Cross-Reference Index
Part NumberManufacturer
50FK420 PRIMARY Sps Technologies, Llc Dba PB Fasteners (USA)
50FK420 Sprague Electric Co World Hqs (USA)
80307 Federal Screw Products, Inc. (USA)
3574 Husco International Inc (USA)
819932-8 Allied Signal Inc Aerospace Equipment Systems Eatontown Site (USA)
Related Parts
5310-00-004-1490INTERCHANGEABLE
NUT,SELF-LOCKING,HEXAGON
5310-00-050-9012INTERCHANGEABLE
NUT,PLAIN,KNURLED
5905-00-190-8885INTERCHANGEABLE
RESISTOR,FIXED,COMPOSITION
6505-00-300-0571INTERCHANGEABLE
SODIUM BORATE
5330-01-016-5778INTERCHANGEABLE
PACKING MATERIAL
3574
5345-01-050-9918INTERCHANGEABLE
ABRASIVE,CARTRIDGE ROLL
08834180307
5905-01-096-3675INTERCHANGEABLE
RESISTOR
3574
5310-01-142-3641INTERCHANGEABLE
NUT,SELF-LOCKING,HEXAGON
50FK-420
5305-01-344-6317INTERCHANGEABLE
SCREW,CAP,SOCKET HEAD
80307
3040-01-447-4121INTERCHANGEABLE
SHAFT,STRAIGHT
3574
1010-01-606-3763INTERCHANGEABLE
LOCK,TRAVEL,SMALL ARMS
01161915

Frequently Asked Questions

What is NSN 5310-00-550-9449?

NSN 5310-00-550-9449 is a Nut,self-Locking,slotted,hexagon, manufactured by Sps Technologies, Llc Dba PB Fasteners, classified under FSC 5310 (No Item Name Available). Status: active.

What are the part numbers for NSN 5310-00-550-9449?

NSN 5310-00-550-9449 has 5 cross-referenced part numbers: 50FK420 (Sps Technologies, Llc Dba PB Fasteners), 50FK420 (Sprague Electric Co World Hqs), 80307 (Federal Screw Products, Inc.), 3574 (Husco International Inc), 819932-8 (Allied Signal Inc Aerospace Equipment Systems Eatontown Site).

What NSN replaces 5310-00-550-9449?

There are 11 known substitutes for 5310-00-550-9449: 5310-00-004-1490, 5310-00-050-9012, 5905-00-190-8885 and 8 more. Verify interchangeability with system specifications before substitution.

What are the specifications of 50FK420?

Key specifications for 50FK420: Thread Direction: RIGHT-HAND; Locking Feature: PREVAILING TORQUE ALL METAL DESIGN; Bearing Surface Type: WASHER FACED; Nominal Thread Size: 0.250 INCHES IN. 13 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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