PartsTable TECHNICAL DATA SHEET
JULY 2026Technical Data Sheet

W-100Flux,welding

Allen L B Co Inc · NSN 3439-00-255-9940 · FSC 3439 · No Item Name Available
Verified by PartsTable
NSN 3439-00-255-9940 — this item is cataloged by the U.S. Government under National Stock Number 3439-00-255-9940. Primary manufacturer part number: W-100.
Features
  • Flux,welding — FSC 3439
  • Physical Form: POWDER
  • Material for Which Formulated: IRON, CAST AND IRON, MALLEABLE AND STEEL, CORROSION RESISTING AND STEEL
  • Mesh Size: 40
  • Nondefinitive Spec/std Data: C TYPE
  • Content Within Each Unit Package: 5 LB LBS
  • Welding Process for Which Designed: GAS
  • 3 verified cross-references
Applications
  • Industrial maintenance and repair
  • Government and military logistics
  • Equipment overhaul and refurbishment
General Description

The Flux,welding, cataloged under National Stock Number 3439-00-255-9940, is classified within Federal Supply Class 3439 (No Item Name Available) of the Metalworking Machinery (continued) group. The primary manufacturer of record is Allen L B Co Inc. Government technical data includes 6 verified specifications, sourced from the Federal Logistics Information System (FLIS). This item has 3 commercial cross-references from 3 manufacturers, enabling identification through both NSN and commercial part number lookups. 12 verified substitutes exist in the FLIS interchangeability database. Current acquisition status: Active.

Technical Specifications
ParameterValue
NSN3439-00-255-9940
Primary Part NumberW-100
Item NameFlux,welding
FSC / FSG3439 / 34 — No Item Name Available
ManufacturerAllen L B Co Inc
StatusACTIVE
Physical FormPOWDER
Material for Which FormulatedIRON, CAST AND IRON, MALLEABLE AND STEEL, CORROSION RESISTING AND STEEL
Mesh Size40
Nondefinitive Spec/std DataC TYPE
Content Within Each Unit Package5 LB LBS
Welding Process for Which DesignedGAS
Lifecycle & Compliance
Acquisition StatusACTIVE
HAZMATNo
Verified Substitutes 12
5950-00-123-5805W100 INTERCHANGEABLE
Coil,radio Frequency
Wilco Corp
3439-00-255-45801 INTERCHANGEABLE
Flux,welding
Anti-Borax Compound Co Inc
3439-00-260-1267PETERSON NO 1 INTERCHANGEABLE
Flux,brazing
Jo-Jon, Inc Dba Specialty Welding Supply Div Jo-Jon, Incorporated
5950-00-678-0488 INTERCHANGEABLE
Transformer,power
5999-00-868-2964W100 INTERCHANGEABLE
Heater,thermal Release
Ward Leonard Ct Llc
6605-00-972-5365 INTERCHANGEABLE
Compass,corsair
3439-01-011-7858 INTERCHANGEABLE
Soldering Iron,electric
5950-01-079-7022104630 INTERCHANGEABLE
Transformer,power
Champion Industries Inc.
4130-01-261-7987W-100 INTERCHANGEABLE
Filter Element,air Conditioning
Universal Air Filter Co
5330-01-298-3073W100 INTERCHANGEABLE
Gasket
Emglo Products Corp
Cross-Reference Index
Part NumberManufacturer
W-100 Allen L B Co Inc (USA)
MILF16136 Military Specifications Promulgated by Military Departments/agencies Under Authority of Defense Standardization Manual 4120 3-M
1 Anti-Borax Compound Co Inc (USA)
Related Parts
5950-00-123-5805INTERCHANGEABLE
COIL,RADIO FREQUENCY
W100
3439-00-255-4580INTERCHANGEABLE
FLUX,WELDING
1
3439-00-260-1267INTERCHANGEABLE
FLUX,BRAZING
PETERSON NO 1
5950-00-678-0488INTERCHANGEABLE
TRANSFORMER,POWER
5999-00-868-2964INTERCHANGEABLE
HEATER,THERMAL RELEASE
W100
6605-00-972-5365INTERCHANGEABLE
COMPASS,CORSAIR
3439-01-011-7858INTERCHANGEABLE
SOLDERING IRON,ELECTRIC
5950-01-079-7022INTERCHANGEABLE
TRANSFORMER,POWER
104630
4130-01-261-7987INTERCHANGEABLE
FILTER ELEMENT,AIR CONDITIONING
W-100
5330-01-298-3073INTERCHANGEABLE
GASKET
W100
5905-01-314-9241INTERCHANGEABLE
HOLDER,RESISTOR
4130-01-320-9203INTERCHANGEABLE
CORE,FILTER-DRIER
RC-10098-HH

Frequently Asked Questions

What is NSN 3439-00-255-9940?

NSN 3439-00-255-9940 is a Flux,welding, manufactured by Allen L B Co Inc, classified under FSC 3439 (No Item Name Available). Status: active.

What are the part numbers for NSN 3439-00-255-9940?

NSN 3439-00-255-9940 has 3 cross-referenced part numbers: W-100 (Allen L B Co Inc), MILF16136 (Military Specifications Promulgated by Military Departments/agencies Under Authority of Defense Standardization Manual 4120 3-M), 1 (Anti-Borax Compound Co Inc).

What NSN replaces 3439-00-255-9940?

There are 12 known substitutes for 3439-00-255-9940: 5950-00-123-5805, 3439-00-255-4580, 3439-00-260-1267 and 9 more. Verify interchangeability with system specifications before substitution.

What are the specifications of W-100?

Key specifications for W-100: Physical Form: POWDER; Material for Which Formulated: IRON, CAST AND IRON, MALLEABLE AND STEEL, CORROSION RESISTING AND STEEL; Mesh Size: 40; Nondefinitive Spec/std Data: C TYPE. 6 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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