The Nut,respirator, cataloged under National Stock Number 4240-01-252-0091, is classified within Federal Supply Class 4240 (Safety and Rescue Equipment) of the Fire Fighting, Rescue, and Safety Equipment group. The manufacturer of record is Mine Safety Appliances Company. Government technical data includes 2 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. Current acquisition status: Active.
| Parameter | Value |
|---|---|
| NSN | 4240-01-252-0091 |
| Primary Part Number | 629657 |
| Item Name | Nut,respirator |
| FSC / FSG | 4240 / 42 — Safety and Rescue Equipment |
| Manufacturer | Mine Safety Appliances Company |
| Status | ACTIVE |
| General Characteristics Item Description | SOLE SOURCE REQUIRED BY STATUTE 6.302 |
| Criticality Code Justification | TEXT |
| Acquisition Status | ACTIVE |
| DEMIL Code | DEMIL A — No Demilitarization Required |
| Hazard | Possible hazard — SDS may be required (DLA HMIC P) |
| Criticality Code | Y |
| Part Number | Manufacturer |
|---|---|
| 629657 PRIMARY | Mine Safety Appliances Company (USA) |
NSN 4240-01-252-0091 is a Nut,respirator, manufactured by Mine Safety Appliances Company, classified under FSC 4240, Safety and Rescue Equipment. Status: active.
NSN 4240-01-252-0091 has 1 manufacturer part number on file: 629657 (Mine Safety Appliances Company).
Key specifications for 629657: General Characteristics Item Description: SOLE SOURCE REQUIRED BY STATUTE 6.302; Criticality Code Justification: TEXT. 2 specifications are documented in the U.S. Government catalog.
Possible hazard — SDS may be required (DLA HMIC P). 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.