The Seat,helical Compression Spring, cataloged under National Stock Number 5340-01-388-4143, is classified within Federal Supply Class 5340 (Hardware, Commercial) of the Hardware and Abrasives group. The manufacturer of record is Parker-Hannifin Corporation Dba Pneutronics Div Hydraulic Valve Division. Government technical data includes 7 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through both NSN and commercial part number lookups. 1 additional reference document (drawings, advisory and superseded references) is recorded in the U.S. Government catalog. Current acquisition status: Active. Unit of issue: EA.
| Parameter | Value |
|---|---|
| NSN | 5340-01-388-4143 |
| Primary Part Number | 21453001 |
| Item Name | Seat,helical Compression Spring |
| FSC / FSG | 5340 / 53 — Hardware, Commercial |
| Manufacturer | Parker-Hannifin Corporation Dba Pneutronics Div Hydraulic Valve Division |
| Status | ACTIVE |
| First Step Diameter | 0.9000 INCHES NOMINAL IN |
| End Diameter | 0.6250 INCHES NOMINAL IN |
| Design Type | SOLID |
| Style Designator | SEAT |
| Spherical Seat Top Radius | 0.2730 INCHES NOMINAL IN |
| Bore Diameter | 0.5000 INCHES NOMINAL IN |
| Material | STEEL |
| 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 |
|---|---|
| 21453001 PRIMARY | Parker-Hannifin Corporation Dba Pneutronics Div Hydraulic Valve Division (USA) |
| Reference | Meaning |
|---|---|
| 21453001 | 3/9 Design control — primary reference Parker Hannifin Corporation Dba Gresen Hydraulics Div Hydraulic Valve Division |
NSN 5340-01-388-4143 is a Seat,helical Compression Spring, manufactured by Parker-Hannifin Corporation Dba Pneutronics Div Hydraulic Valve Division, classified under FSC 5340, Hardware, Commercial. Status: active.
NSN 5340-01-388-4143 has 1 manufacturer part number on file: 21453001 (Parker-Hannifin Corporation Dba Pneutronics Div Hydraulic Valve Division).
Key specifications for 21453001: Overall Height: 0.4000 INCHES NOMINAL IN; First Step Diameter: 0.9000 INCHES NOMINAL IN; End Diameter: 0.6250 INCHES NOMINAL IN; Design Type: SOLID. 7 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.