The Seat,helical Compression Spring, cataloged under National Stock Number 5340-00-812-6418, is classified within Federal Supply Class 5340 (Hardware, Commercial) of the Hardware and Abrasives group. The manufacturer of record is Rtx Corporation Dba Pratt & Whitney Div Pratt &whitney. Government technical data includes 10 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. Unit of issue: EA.
| Parameter | Value |
|---|---|
| NSN | 5340-00-812-6418 |
| Primary Part Number | 408398 |
| Item Name | Seat,helical Compression Spring |
| FSC / FSG | 5340 / 53 — Hardware, Commercial |
| Manufacturer | Rtx Corporation Dba Pratt & Whitney Div Pratt &whitney |
| Status | ACTIVE |
| FSC Application Data | ENGINE FUEL SYSTEM,AIRCRAFT |
| First Step Diameter | 0.8100 INCHES NOMINAL IN |
| End Diameter | 0.6050 INCHES NOMINAL IN |
| Distance From End to First Step | 0.1900 INCHES NOMINAL IN |
| Design Type | SOLID |
| Style Designator | SEAT |
| Counterbore Length | 0.1950 INCHES NOMINAL IN |
| Counterbore Diameter | 0.5150 INCHES NOMINAL IN |
| Bore Diameter | 0.3680 INCHES MINIMUM AND 0.3720 INCHES MAXIMUM IN |
| Material | NICKEL ALLOY |
| Acquisition Status | ACTIVE |
| DEMIL Code | DEMIL A — No Demilitarization Required |
| Hazard | Possible hazard — SDS may be required (DLA HMIC P) |
| Criticality Code | X |
| Unit of Issue | EA |
| Part Number | Manufacturer |
|---|---|
| 408398 PRIMARY | Rtx Corporation Dba Pratt & Whitney Div Pratt &whitney (USA) |
NSN 5340-00-812-6418 is a Seat,helical Compression Spring, manufactured by Rtx Corporation Dba Pratt & Whitney Div Pratt &whitney, classified under FSC 5340, Hardware, Commercial. Status: active.
NSN 5340-00-812-6418 has 1 manufacturer part number on file: 408398 (Rtx Corporation Dba Pratt & Whitney Div Pratt &whitney).
Key specifications for 408398: Overall Height: 0.2800 INCHES NOMINAL IN; FSC Application Data: ENGINE FUEL SYSTEM,AIRCRAFT; First Step Diameter: 0.8100 INCHES NOMINAL IN; End Diameter: 0.6050 INCHES NOMINAL IN. 10 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.