PartsTable TECHNICAL DATA SHEET
JULY 2026Technical Data Sheet

WILLSON WELD 11Lens,helmet,welder's

Sperian Eye & Face Protection, Inc. · NSN 4240-00-540-2421 · FSC 4240 · No Item Name Available
Verified by PartsTable
NSN 4240-00-540-2421 — this item is cataloged by the U.S. Government under National Stock Number 4240-00-540-2421. Primary manufacturer part number: WILLSON WELD 11.
Features
  • Lens,helmet,welder's — FSC 4240
  • Departure From Cited Designator: AS MODIFIED BY NATIONAL BUREAU OF STANDARDS SHADE NUMBER
  • Material: GLASS OR PLASTIC
  • Lens Type: FILTER
  • National Bureau of Standards Shade Number: CO-BS 11
  • Nondefinitive Spec/std Data: A STYLE AND III TYPE
  • 11 verified cross-references
  • Primary manufacturer: Sperian Eye & Face Protection, Inc.
Applications
  • Applications requiring Glass or Plastic construction
General Description

The Lens,helmet,welder's, cataloged under National Stock Number 4240-00-540-2421, is classified within Federal Supply Class 4240 (No Item Name Available) of the Fire Fighting, Rescue, and Safety Equipment group. The primary manufacturer of record is Sperian Eye & Face Protection, Inc.. Government technical data includes 5 verified specifications, sourced from the Federal Logistics Information System (FLIS). This item has 11 commercial cross-references from 10 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
NSN4240-00-540-2421
Primary Part NumberWILLSON WELD 11
Item NameLens,helmet,welder's
FSC / FSG4240 / 42 — No Item Name Available
ManufacturerSperian Eye & Face Protection, Inc.
StatusCANCELLED
Departure From Cited DesignatorAS MODIFIED BY NATIONAL BUREAU OF STANDARDS SHADE NUMBER
MaterialGLASS OR PLASTIC
Lens TypeFILTER
National Bureau of Standards Shade NumberCO-BS 11
Nondefinitive Spec/std DataA STYLE AND III TYPE
Lifecycle & Compliance
Acquisition StatusCANCELLED
HAZMATNo
Verified Substitutes 12
5895-00-005-0154 INTERCHANGEABLE
Mixer Stage,frequency
5930-00-126-2615M1-1 INTERCHANGEABLE
Switch,sensitive
Edmunson Electrical Ltd
7490-00-322-5615 INTERCHANGEABLE
Tapewriter
2920-00-540-8343J12 INTERCHANGEABLE
Spark Plug
Champion Aerospace Llc
5930-00-847-79841236001P1 INTERCHANGEABLE
Switch,lever
Bae Systems Information and Electronic Systems Integration Inc. Dba Bae Systems
4720-00-990-167626603 INTERCHANGEABLE
Hose,preformed
Gates Corporation
6695-01-187-7263M1-5 INTERCHANGEABLE
Bezel,instrument Mounting
Orange Research Inc
5340-01-252-3556P562649 INTERCHANGEABLE
Magnet,permanent
Donaldson Company, Inc.
6515-01-367-2454M-11 INTERCHANGEABLE
Shell,fabrication,orthotic
Klm Laboratories, Inc
5962-01-376-48880N445082-1 INTERCHANGEABLE
Microcircuit,digital
National Security Agency
Cross-Reference Index
Part NumberManufacturer
WILLSON WELD 11 Sperian Eye & Face Protection, Inc. (USA)
WILLSON WELD NO. 11 Honeywell Safety Products Usa, Inc. (USA)
GLENDALE NO. 11 Glendale Protective Technologies, Inc. (USA)
MONARCH NO. 11 Fibre-Metal Products Co Inc (USA)
CESCOWELD NO. 11 Cesco Safety Products (USA)
GGG-H-211 Federal Specifications Promulgated by General Services Administration Washington DC (USA)
NORTON MH 11 Siebe North Inc North Safety Equipment Div (USA)
FILTER WELD NO. 11 Aearo Company (USA)
M11 Siebe North Inc North Safety Equipment Div (USA)
WILLSON WELD NO. 11 Dalloz Safety (USA)
50P/11 North Safety Products L.l.c. Dba North Safety Products (USA)
Related Parts
5895-00-005-0154INTERCHANGEABLE
MIXER STAGE,FREQUENCY
5930-00-126-2615INTERCHANGEABLE
SWITCH,SENSITIVE
M1-1
7490-00-322-5615INTERCHANGEABLE
TAPEWRITER
2920-00-540-8343INTERCHANGEABLE
SPARK PLUG
J12
5930-00-847-7984INTERCHANGEABLE
SWITCH,LEVER
1236001P1
4720-00-990-1676INTERCHANGEABLE
HOSE,PREFORMED
26603
6695-01-187-7263INTERCHANGEABLE
BEZEL,INSTRUMENT MOUNTING
M1-5
5340-01-252-3556INTERCHANGEABLE
MAGNET,PERMANENT
P562649
6515-01-367-2454INTERCHANGEABLE
SHELL,FABRICATION,ORTHOTIC
M-11
5962-01-376-4888INTERCHANGEABLE
MICROCIRCUIT,DIGITAL
0N445082-1
2815-01-503-4736INTERCHANGEABLE
ENGINE,DIESEL
M 11
6515-01-508-8465INTERCHANGEABLE
ELECTRODE,COAGULATION

Frequently Asked Questions

What is NSN 4240-00-540-2421?

NSN 4240-00-540-2421 is a Lens,helmet,welder's, manufactured by Sperian Eye & Face Protection, Inc., classified under FSC 4240 (No Item Name Available). Status: cancelled.

What are the part numbers for NSN 4240-00-540-2421?

NSN 4240-00-540-2421 has 11 cross-referenced part numbers: WILLSON WELD 11 (Sperian Eye & Face Protection, Inc.), WILLSON WELD NO. 11 (Honeywell Safety Products Usa, Inc.), GLENDALE NO. 11 (Glendale Protective Technologies, Inc.), MONARCH NO. 11 (Fibre-Metal Products Co Inc), CESCOWELD NO. 11 (Cesco Safety Products) and 6 more.

What NSN replaces 4240-00-540-2421?

There are 12 known substitutes for 4240-00-540-2421: 5895-00-005-0154, 5930-00-126-2615, 7490-00-322-5615 and 9 more. Verify interchangeability with system specifications before substitution.

What are the specifications of WILLSON WELD 11?

Key specifications for WILLSON WELD 11: Departure From Cited Designator: AS MODIFIED BY NATIONAL BUREAU OF STANDARDS SHADE NUMBER; Overall Width: 2.000 INCHES NOMINAL IN; Material: GLASS OR PLASTIC; Lens Type: FILTER. 7 total characteristics are documented in the Federal Logistics Information System.

Is NSN 4240-00-540-2421 still in active supply?

NSN 4240-00-540-2421 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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