The Window,observation, cataloged under National Stock Number 9340-01-538-5221, is classified within Federal Supply Class 9340 (Glass Fabricated Materials) of the Nonmetallic Fabricated Materials group. The manufacturer of record is Curtiss-Wright Flow Control Corporation Dba Curtiss-Wright Flow Control Co Div Curtiss-Wright / Nu-Torque. Government technical data includes 4 specifications, cited from the U.S. Government catalog. The record lists 1 manufacturer part number for this item, enabling identification through both NSN and commercial part number lookups. 1 additional reference document (drawings, advisory and superseded references) is recorded in the U.S. Government catalog. 1 item shares a part number with this NSN in the catalog (possible match — not a government interchangeability claim). Current acquisition status: Active.
| Parameter | Value |
|---|---|
| NSN | 9340-01-538-5221 |
| Primary Part Number | 12424-4 |
| Item Name | Window,observation |
| FSC / FSG | 9340 / 93 — Glass Fabricated Materials |
| Manufacturer | Curtiss-Wright Flow Control Corporation Dba Curtiss-Wright Flow Control Co Div Curtiss-Wright / Nu-Torque |
| Status | ACTIVE |
| Overall Diameter | 2.000 INCHES NOMINAL IN |
| Overall Thickness | 0.250 INCHES NOMINAL IN |
| Style Designator | CIRCULAR |
| Material | GLASS BOROSILICATE |
| Acquisition Status | ACTIVE |
| DEMIL Code | DEMIL A — No Demilitarization Required |
| Hazard | No hazard code in the DLA record (HMIC N) |
| Criticality Code | X |
| Part Number | Manufacturer |
|---|---|
| 12424-4 PRIMARY | Curtiss-Wright Flow Control Corporation Dba Curtiss-Wright Flow Control Co Div Curtiss-Wright / Nu-Torque (USA) |
| Reference | Meaning |
|---|---|
| 12274PL FIND NO 24 | D/9 Drawing number reference only Curtiss-Wright Flow Control Corporation Dba Curtiss-Wright Flow Control Co Div Curtiss-Wright / Nu-Torque |
NSN 9340-01-538-5221 is a Window,observation, manufactured by Curtiss-Wright Flow Control Corporation Dba Curtiss-Wright Flow Control Co Div Curtiss-Wright / Nu-Torque, classified under FSC 9340, Glass Fabricated Materials. Status: active.
NSN 9340-01-538-5221 has 1 manufacturer part number on file: 12424-4 (Curtiss-Wright Flow Control Corporation Dba Curtiss-Wright Flow Control Co Div Curtiss-Wright / Nu-Torque).
1 possible match (shared part number, not a government interchangeability claim): 2510-01-665-6820. Verify interchangeability with system specifications before substitution.
Key specifications for 12424-4: Overall Diameter: 2.000 INCHES NOMINAL IN; Overall Thickness: 0.250 INCHES NOMINAL IN; Style Designator: CIRCULAR; Special Features: ITEM HAS CAPABILITY FOR 28-DEGREE ROTATION. 4 specifications are documented in the U.S. Government catalog.
No hazard code in the DLA record (HMIC N). Hazard information on this page is shown exactly as it appears in the DLA record.
U.S. Government catalog: edition PUBLOGDVD v12.0.0 (OCT 2026), edition date 2026-10-01, retrieved 2026-10-16.
U.S. Government catalog: edition PUBLOGDVD v12.0.0 (OCT 2026), edition date 2026-10-01, retrieved 2026-10-18.