PartsTable TECHNICAL DATA SHEET
JULY 2026Technical Data Sheet

B18.3Key,socket Head Screw

The American Society of Mechanical Engineers · NSN 5120-00-249-9670 · FSC 5120 · No Item Name Available
Verified by PartsTable
NSN 5120-00-249-9670 — this item is cataloged by the U.S. Government under National Stock Number 5120-00-249-9670. Primary manufacturer part number: B18.3.
Features
  • Key,socket Head Screw — FSC 5120
  • Wrenching Surface Shape: SPLINE BOTH ENDS EXTERNAL
  • Style Designator: L-HANDLE
  • Short Arm Length: 0.469 INCHES MINIMUM AND 0.656 INCHES MAXIMUM IN
  • Long Arm Length: 1.656 INCHES MINIMUM AND 1.844 INCHES MAXIMUM IN
  • Wrenching Surface Size: 0.072 INCHES NOMINAL BOTH ENDS IN
  • Wrenching Surface Flute Quantity: 6
  • Specification/standard Data: 05047-ASME B18.3 PROFESSIONAL/INDUSTRIAL ASSOCIATION STANDARD
Applications
  • Structural fastening and assembly
  • Equipment mounting
  • Panel and housing attachment
  • Applications requiring Steel Overall construction
General Description

The Key,socket Head Screw, cataloged under National Stock Number 5120-00-249-9670, is classified within Federal Supply Class 5120 (No Item Name Available) of the Hand Tools group. The primary manufacturer of record is The American Society of Mechanical Engineers. Government technical data includes 9 verified specifications, sourced from the Federal Logistics Information System (FLIS). This item has 14 commercial cross-references from 13 manufacturers, enabling identification through both NSN and commercial part number lookups. 12 verified substitutes exist in the FLIS interchangeability database. Current acquisition status: Cancelled.

Technical Specifications
ParameterValue
NSN5120-00-249-9670
Primary Part NumberB18.3
Item NameKey,socket Head Screw
FSC / FSG5120 / 51 — No Item Name Available
ManufacturerThe American Society of Mechanical Engineers
StatusCANCELLED
Wrenching Surface ShapeSPLINE BOTH ENDS EXTERNAL
Style DesignatorL-HANDLE
Short Arm Length0.469 INCHES MINIMUM AND 0.656 INCHES MAXIMUM IN
Long Arm Length1.656 INCHES MINIMUM AND 1.844 INCHES MAXIMUM IN
Wrenching Surface Size0.072 INCHES NOMINAL BOTH ENDS IN
Wrenching Surface Flute Quantity6
Specification/standard Data05047-ASME B18.3 PROFESSIONAL/INDUSTRIAL ASSOCIATION STANDARD
Features ProvidedSHORT SERIES
MaterialSTEEL OVERALL
Lifecycle & Compliance
Acquisition StatusCANCELLED
HAZMATNo
Verified Substitutes 12
4810-00-032-8178U7250 INTERCHANGEABLE
Valve,solenoid
Triumph Thermal Systems, Llc
6240-00-060-2941683 INTERCHANGEABLE
Lamp,incandescent
Chicago Miniature Lighting Llc Dba Chicago Miniature Optoelectron
3110-00-155-8439MS7 INTERCHANGEABLE
Bearing,ball,annular
Fag Bearings Corporation
5985-00-182-64925072 INTERCHANGEABLE
Coupler,directional
Narda Holdings, Inc. Dba Narda-Miteq Div Narda-Miteq
5360-00-209-7649 INTERCHANGEABLE
Spring,helical,compression
5330-00-259-938812000597-5 INTERCHANGEABLE
Seal,plain Encased
Army, United States Department of the Dba Rock Island Arsenal Jmtc
1005-00-368-96865072 INTERCHANGEABLE
Trigger
Smith & Wesson Sales Company
3433-00-467-1184507-2 INTERCHANGEABLE
Cutting Machine,gas,portable
Esab North America Inc
3110-00-540-4580102668-617 INTERCHANGEABLE
Bearing,ball,annular
Navair and Navsea Managed Original Design Activity Dwg Not Material/parts Supplier
5310-00-613-71702055-440 INTERCHANGEABLE
Nut,plain,hexagon
Matthew Warren, Inc Dba Raf Electronic Hardware Div Raf Electronic Hardware, Llc
Cross-Reference Index
Part NumberManufacturer
B18.3 The American Society of Mechanical Engineers (USA)
8220-1C Cessna Aircraft Co Arc Avionics Div (USA)
S318-1004P27 Raytheon Co Equipment Development Lab (USA)
9073301 Us Army Aviation and Missile Command (USA)
A-A-2473 Federal Commercial Item Description Promulgated by General Services Administration Washington DC (USA)
GGG-K-275 Federal Specifications Promulgated by General Services Administration Washington DC (USA)
S-072 H-K Connecticut Holding Company (USA)
GGG-K-275 TY2CL1 General Services Administration Federal Supply Service (USA)
5072 Gc/waldom Inc (USA)
024-0167-000 Rockwell Collins, Inc. Dba Collins Aerospace Government Systems Div Collins Aerospace - Government Systems (USA)
MS7 Sna Germany Gmbh (DEU)
S072 Bristol Babcock Inc Instruments-Systems Div Sub of Babcock Intl Inc (USA)
318-1051P2 Raytheon Co Equipment Development Lab (USA)
S-072-6 Mahalo Industries Inc Dba Bristol Wrench Co. (USA)
Related Parts
4810-00-032-8178INTERCHANGEABLE
VALVE,SOLENOID
U7250
6240-00-060-2941INTERCHANGEABLE
LAMP,INCANDESCENT
683
3110-00-155-8439INTERCHANGEABLE
BEARING,BALL,ANNULAR
MS7
5985-00-182-6492INTERCHANGEABLE
COUPLER,DIRECTIONAL
5072
5360-00-209-7649INTERCHANGEABLE
SPRING,HELICAL,COMPRESSION
5330-00-259-9388INTERCHANGEABLE
SEAL,PLAIN ENCASED
12000597-5
1005-00-368-9686INTERCHANGEABLE
TRIGGER
5072
3433-00-467-1184INTERCHANGEABLE
CUTTING MACHINE,GAS,PORTABLE
507-2
3110-00-540-4580INTERCHANGEABLE
BEARING,BALL,ANNULAR
102668-617
5310-00-613-7170INTERCHANGEABLE
NUT,PLAIN,HEXAGON
2055-440
3040-00-802-4446INTERCHANGEABLE
CONNECTING LINK,RIGID
907330-1
5360-00-962-2590INTERCHANGEABLE
SPRING,HELICAL,COMPRESSION
5072

Frequently Asked Questions

What is NSN 5120-00-249-9670?

NSN 5120-00-249-9670 is a Key,socket Head Screw, manufactured by The American Society of Mechanical Engineers, classified under FSC 5120 (No Item Name Available). Status: cancelled.

What are the part numbers for NSN 5120-00-249-9670?

NSN 5120-00-249-9670 has 14 cross-referenced part numbers: B18.3 (The American Society of Mechanical Engineers), 8220-1C (Cessna Aircraft Co Arc Avionics Div), S318-1004P27 (Raytheon Co Equipment Development Lab), 9073301 (Us Army Aviation and Missile Command), A-A-2473 (Federal Commercial Item Description Promulgated by General Services Administration Washington DC) and 9 more.

What NSN replaces 5120-00-249-9670?

There are 12 known substitutes for 5120-00-249-9670: 4810-00-032-8178, 6240-00-060-2941, 3110-00-155-8439 and 9 more. Verify interchangeability with system specifications before substitution.

What are the specifications of B18.3?

Key specifications for B18.3: Wrenching Surface Shape: SPLINE BOTH ENDS EXTERNAL; Style Designator: L-HANDLE; Short Arm Length: 0.469 INCHES MINIMUM AND 0.656 INCHES MAXIMUM IN; Long Arm Length: 1.656 INCHES MINIMUM AND 1.844 INCHES MAXIMUM IN. 10 total characteristics are documented in the Federal Logistics Information System.

Is NSN 5120-00-249-9670 still in active supply?

NSN 5120-00-249-9670 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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