PartsTable TECHNICAL DATA SHEET
JULY 2026Technical Data Sheet

B18.3Key,socket Head Screw

The American Society of Mechanical Engineers · NSN 5120-00-725-7451 · FSC 5120 · No Item Name Available
Verified by PartsTable
NSN 5120-00-725-7451 — this item is cataloged by the U.S. Government under National Stock Number 5120-00-725-7451. Primary manufacturer part number: B18.3.
Features
  • Key,socket Head Screw — FSC 5120
  • Long Arm Length: 7.406 INCHES MINIMUM AND 7.594 INCHES MAXIMUM IN
  • Short Arm Length: 1.406 INCHES MINIMUM AND 1.594 INCHES MAXIMUM IN
  • Nondefinitive Spec/std Data: 2 TYPE
  • Style Designator: L-HANDLE
  • Wrenching Surface Shape: HEXAGON BOTH ENDS EXTERNAL
  • Features Provided: LONG SERIES
  • Wrenching Surface Size: 0.438 INCHES NOMINAL BOTH ENDS IN
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 5120-00-725-7451, 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 7 commercial cross-references from 7 manufacturers, enabling identification through both NSN and commercial part number lookups. 10 verified substitutes exist in the FLIS interchangeability database. Current acquisition status: Active.

Technical Specifications
ParameterValue
NSN5120-00-725-7451
Primary Part NumberB18.3
Item NameKey,socket Head Screw
FSC / FSG5120 / 51 — No Item Name Available
ManufacturerThe American Society of Mechanical Engineers
StatusACTIVE
Long Arm Length7.406 INCHES MINIMUM AND 7.594 INCHES MAXIMUM IN
Short Arm Length1.406 INCHES MINIMUM AND 1.594 INCHES MAXIMUM IN
Nondefinitive Spec/std Data2 TYPE
Style DesignatorL-HANDLE
Wrenching Surface ShapeHEXAGON BOTH ENDS EXTERNAL
Features ProvidedLONG SERIES
Wrenching Surface Size0.438 INCHES NOMINAL BOTH ENDS IN
MaterialSTEEL OVERALL
Specification/standard Data05047-ASME B18.3 PROFESSIONAL/INDUSTRIAL ASSOCIATION STANDARD
Lifecycle & Compliance
Acquisition StatusACTIVE
HAZMATNo
Verified Substitutes 10
5120-00-198-540113802 INTERCHANGEABLE
Key,socket Head Screw
Bondhus Corp
5120-00-198-5405 INTERCHANGEABLE
Key,socket Head Screw
5120-00-198-5407 INTERCHANGEABLE
Key,socket Head Screw
5120-00-198-541013910 INTERCHANGEABLE
Key,socket Head Screw
Bondhus Corp
5120-00-204-1995 INTERCHANGEABLE
Key,socket Head Screw
5120-00-221-803615206 INTERCHANGEABLE
Key,socket Head Screw
Eklind Tool Co
5120-00-293-008013904 INTERCHANGEABLE
Key,socket Head Screw
Bondhus Corp
5120-00-293-1476 INTERCHANGEABLE
Key,socket Head Screw
5310-00-638-658058023 INTERCHANGEABLE
Nut,plain,plate
Naval Inventory Control Point Mechanicsburg
5120-01-017-9535 INTERCHANGEABLE
Key Set,socket Head Screw
Cross-Reference Index
Part NumberManufacturer
B18.3 The American Society of Mechanical Engineers (USA)
A-A-2932 Federal Commercial Item Description Promulgated by General Services Administration Washington DC (USA)
GGG-K-275 TY1CL2 General Services Administration Federal Supply Service (USA)
58023 Easco Hand Tools Inc Dba Danaher Tool Group Div Danaher Tool Group Easco Hand Tools Inc. (USA)
F23713 Stanley-Proto Industrial Works Div of the Stanley Works (USA)
58023 Apex Tool Group, Llc Dba Nicholson (USA)
GGG-K-275 Federal Specifications Promulgated by General Services Administration Washington DC (USA)
Related Parts
5120-00-198-5401INTERCHANGEABLE
KEY,SOCKET HEAD SCREW
13802
5120-00-198-5405INTERCHANGEABLE
KEY,SOCKET HEAD SCREW
5120-00-198-5407INTERCHANGEABLE
KEY,SOCKET HEAD SCREW
5120-00-198-5410INTERCHANGEABLE
KEY,SOCKET HEAD SCREW
13910
5120-00-204-1995INTERCHANGEABLE
KEY,SOCKET HEAD SCREW
5120-00-221-8036INTERCHANGEABLE
KEY,SOCKET HEAD SCREW
15206
5120-00-293-0080INTERCHANGEABLE
KEY,SOCKET HEAD SCREW
13904
5120-00-293-1476INTERCHANGEABLE
KEY,SOCKET HEAD SCREW
5310-00-638-6580INTERCHANGEABLE
NUT,PLAIN,PLATE
58023
5120-01-017-9535INTERCHANGEABLE
KEY SET,SOCKET HEAD SCREW

Frequently Asked Questions

What is NSN 5120-00-725-7451?

NSN 5120-00-725-7451 is a Key,socket Head Screw, manufactured by The American Society of Mechanical Engineers, classified under FSC 5120 (No Item Name Available). Status: active.

What are the part numbers for NSN 5120-00-725-7451?

NSN 5120-00-725-7451 has 7 cross-referenced part numbers: B18.3 (The American Society of Mechanical Engineers), A-A-2932 (Federal Commercial Item Description Promulgated by General Services Administration Washington DC), GGG-K-275 TY1CL2 (General Services Administration Federal Supply Service), 58023 (Easco Hand Tools Inc Dba Danaher Tool Group Div Danaher Tool Group Easco Hand Tools Inc.), F23713 (Stanley-Proto Industrial Works Div of the Stanley Works) and 2 more.

What NSN replaces 5120-00-725-7451?

There are 10 known substitutes for 5120-00-725-7451: 5120-00-198-5401, 5120-00-198-5405, 5120-00-198-5407 and 7 more. Verify interchangeability with system specifications before substitution.

What are the specifications of B18.3?

Key specifications for B18.3: Long Arm Length: 7.406 INCHES MINIMUM AND 7.594 INCHES MAXIMUM IN; Short Arm Length: 1.406 INCHES MINIMUM AND 1.594 INCHES MAXIMUM IN; Overall Length: 7.844 INCHES MINIMUM AND 8.032 INCHES MAXIMUM IN; Nondefinitive Spec/std Data: 2 TYPE. 10 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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