The Block,adjusting Screw, cataloged under National Stock Number 4820-01-278-9903, is classified within Federal Supply Class 4820 (Valves, Nonpowered) of the Valves group. The manufacturer of record is Automatic Switch Company Dba Asco. Government technical data includes 1 specification, cited from the U.S. Government catalog. The record lists 2 manufacturer part numbers 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through both NSN and commercial part number lookups. 1 additional reference document (drawings, advisory and superseded references) is recorded in the U.S. Government catalog. Current acquisition status: Active.
| Parameter | Value |
|---|---|
| NSN | 4820-01-278-9903 |
| Primary Part Number | FV31-991-1 |
| Item Name | Block,adjusting Screw |
| FSC / FSG | 4820 / 48 — Valves, Nonpowered |
| Manufacturer | Automatic Switch Company Dba Asco |
| Status | ACTIVE |
| General Characteristics Item Description | BRASS ASTM B16 |
| 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 |
|---|---|
| AV202-55 ITEM 36 | Automatic Switch Company Dba Asco (USA) |
| FV31-991-1 PRIMARY | Automatic Switch Company Dba Asco (USA) |
| Reference | Meaning |
|---|---|
| AV202-055 | D/9 Drawing number reference only Automatic Switch Company Dba Asco |
NSN 4820-01-278-9903 is a Block,adjusting Screw, manufactured by Automatic Switch Company Dba Asco, classified under FSC 4820, Valves, Nonpowered. Status: active.
NSN 4820-01-278-9903 has 2 manufacturer part numbers on file: AV202-55 ITEM 36 (Automatic Switch Company Dba Asco), FV31-991-1 (Automatic Switch Company Dba Asco).
Key specifications for FV31-991-1: General Characteristics Item Description: BRASS ASTM B16. 1 specification is 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.