The Seat,helical Compression Spring, cataloged under National Stock Number 5340-00-118-3597, is classified within Federal Supply Class 5340 (Hardware, Commercial) of the Hardware and Abrasives group. The manufacturer of record is Parker-Hannifin Corporation Div Gas Turbine Fuel Systems. Government technical data includes 13 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 | 5340-00-118-3597 |
| Primary Part Number | 6661521 |
| Item Name | Seat,helical Compression Spring |
| FSC / FSG | 5340 / 53 — Hardware, Commercial |
| Manufacturer | Parker-Hannifin Corporation Div Gas Turbine Fuel Systems |
| Status | ACTIVE |
| FSC Application Data | SEAT,HELICAL COMPRESSION SPRING,ENGINE,AIRCRAFT |
| First Step Diameter | 0.5430 INCHES NOMINAL IN |
| End Diameter | 0.4900 INCHES NOMINAL IN |
| Distance From End to First Step | 0.0840 INCHES NOMINAL IN |
| Design Type | SOLID |
| Style Designator | SEAT |
| Counterbore Length | 0.0850 INCHES NOMINAL IN |
| Second Step Diameter | 0.7500 INCHES NOMINAL IN |
| Counterbore Diameter | 0.5015 INCHES NOMINAL IN |
| First Step Length | 0.0950 INCHES NOMINAL IN |
| Surface Treatment | PASSIVATE |
| Bore Diameter | 0.3770 INCHES NOMINAL IN |
| Material | STEEL CORROSION RESISTING |
| 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 |
|---|---|
| 6661521 PRIMARY | Parker-Hannifin Corporation Div Gas Turbine Fuel Systems (USA) |
NSN 5340-00-118-3597 is a Seat,helical Compression Spring, manufactured by Parker-Hannifin Corporation Div Gas Turbine Fuel Systems, classified under FSC 5340, Hardware, Commercial. Status: active.
NSN 5340-00-118-3597 has 1 manufacturer part number on file: 6661521 (Parker-Hannifin Corporation Div Gas Turbine Fuel Systems).
Key specifications for 6661521: Overall Height: 0.3130 INCHES NOMINAL IN; FSC Application Data: SEAT,HELICAL COMPRESSION SPRING,ENGINE,AIRCRAFT; First Step Diameter: 0.5430 INCHES NOMINAL IN; End Diameter: 0.4900 INCHES NOMINAL IN. 13 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.