PartsTable TECHNICAL DATA SHEET
JULY 2026Technical Data Sheet

F121Socket,socket Wrench

Idsc Holdings Llc Div Snap-on Industrial, a Div. of Idsc Holdings , Llc · NSN 5120-01-661-6779 · FSC 5120 · No Item Name Available
Verified by PartsTable
NSN 5120-01-661-6779 — this item is cataloged by the U.S. Government under National Stock Number 5120-01-661-6779. Primary manufacturer part number: F121.
Features
  • Socket,socket Wrench — FSC 5120
  • Style Designator: INTERNAL-INTERNAL
  • Drive End Shape: SQUARE SINGLE END INTERNAL
  • Wrenching Surface Size: 0.375 INCHES NOMINAL SINGLE END IN
  • Surface Treatment: CHROMIUM OVERALL
  • Wrenching Surface Shape: 12 POINT SINGLE END INTERNAL
  • Drive Surface Size: 0.375 INCHES NOMINAL SINGLE END IN
  • Material: STEEL OVERALL
Applications
  • Applications requiring Steel Overall construction
General Description

The Socket,socket Wrench, cataloged under National Stock Number 5120-01-661-6779, is classified within Federal Supply Class 5120 (No Item Name Available) of the Hand Tools group. The primary manufacturer of record is Idsc Holdings Llc Div Snap-on Industrial, a Div. of Idsc Holdings , Llc. Government technical data includes 8 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: Active.

Technical Specifications
ParameterValue
NSN5120-01-661-6779
Primary Part NumberF121
Item NameSocket,socket Wrench
FSC / FSG5120 / 51 — No Item Name Available
ManufacturerIdsc Holdings Llc Div Snap-on Industrial, a Div. of Idsc Holdings , Llc
StatusACTIVE
Style DesignatorINTERNAL-INTERNAL
Drive End ShapeSQUARE SINGLE END INTERNAL
Wrenching Surface Size0.375 INCHES NOMINAL SINGLE END IN
Surface TreatmentCHROMIUM OVERALL
Wrenching Surface Shape12 POINT SINGLE END INTERNAL
Drive Surface Size0.375 INCHES NOMINAL SINGLE END IN
MaterialSTEEL OVERALL
Features ProvidedMANUAL TOOL
Lifecycle & Compliance
Acquisition StatusACTIVE
HAZMATNo
Verified Substitutes 2
5910-01-049-6559 INTERCHANGEABLE
Capacitor,fixed,mica Dielectric
5120-01-350-1005B-1212 INTERCHANGEABLE
Socket,socket Wrench
Williams J H Industrial Products Inc
Cross-Reference Index
Part NumberManufacturer
11A7000766-1 Devcom Chemical Biological Center Dba Chemical Biological Center Div U.s. Dept of Army (USA)
F121 PRIMARY Idsc Holdings Llc Div Snap-on Industrial, a Div. of Idsc Holdings , Llc (USA)
Related Parts
5910-01-049-6559INTERCHANGEABLE
CAPACITOR,FIXED,MICA DIELECTRIC
5120-01-350-1005INTERCHANGEABLE
SOCKET,SOCKET WRENCH
B-1212

Frequently Asked Questions

What is NSN 5120-01-661-6779?

NSN 5120-01-661-6779 is a Socket,socket Wrench, manufactured by Idsc Holdings Llc Div Snap-on Industrial, a Div. of Idsc Holdings , Llc, classified under FSC 5120 (No Item Name Available). Status: active.

What are the part numbers for NSN 5120-01-661-6779?

NSN 5120-01-661-6779 has 2 cross-referenced part numbers: 11A7000766-1 (Devcom Chemical Biological Center Dba Chemical Biological Center Div U.s. Dept of Army), F121 (Idsc Holdings Llc Div Snap-on Industrial, a Div. of Idsc Holdings , Llc).

What NSN replaces 5120-01-661-6779?

There are 2 known substitutes for 5120-01-661-6779: 5910-01-049-6559, 5120-01-350-1005. Verify interchangeability with system specifications before substitution.

What are the specifications of F121?

Key specifications for F121: Style Designator: INTERNAL-INTERNAL; Drive End Shape: SQUARE SINGLE END INTERNAL; Wrenching Surface Size: 0.375 INCHES NOMINAL SINGLE END IN; Surface Treatment: CHROMIUM OVERALL. 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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