The Seat,helical Compression Spring, cataloged under National Stock Number 5340-01-129-3971, is classified within Federal Supply Class 5340 (Hardware, Commercial) of the Hardware and Abrasives group. Government technical data includes 16 specifications, cited from the U.S. Government catalog. 1 additional reference document (drawings, advisory and superseded references) is recorded in the U.S. Government catalog.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 | 5340-01-129-3971 |
| Item Name | Seat,helical Compression Spring |
| FSC / FSG | 5340 / 53 — Hardware, Commercial |
| Status | ACTIVE |
| Countersink Angle in Deg | 45.0 |
| First Step Diameter | 0.4650 INCHES MINIMUM AND 0.4750 INCHES MAXIMUM IN |
| End Diameter | 0.4290 INCHES NOMINAL IN |
| Countersink Diameter | 0.4700 INCHES NOMINAL IN |
| Surface Treatment Document and Classification | PS13001, MCDONNELL DOUGLAS CORP MFR REF SINGLE TREATMENT RESPONSE |
| Distance From End to First Step | 0.0750 INCHES NOMINAL IN |
| Design Type | SOLID |
| Material Document and Classification | ASTM A582, TYPE 303 ASSN STD SINGLE MATERIAL RESPONSE |
| Counterbore Length | 0.2550 INCHES NOMINAL IN |
| Second Step Diameter | 0.6100 INCHES NOMINAL IN |
| Counterbore Diameter | 0.4000 INCHES NOMINAL IN |
| First Step Length | 0.1700 INCHES NOMINAL IN |
| Surface Treatment | PASSIVATE |
| Chamfer Angle in Deg | 15.0 |
| Bore Diameter | 0.3120 INCHES MINIMUM AND 0.3130 INCHES MAXIMUM IN |
| Material | STEEL COMP 303 |
| 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 |
| Reference | Meaning |
|---|---|
| 287832-1 | 3/2 Design control — primary reference U.S. Government activity |
NSN 5340-01-129-3971 is a Seat,helical Compression Spring, classified under FSC 5340, Hardware, Commercial. Status: active.
Key specifications for 5340-01-129-3971: Overall Height: 0.3250 INCHES NOMINAL IN; Countersink Angle in Deg: 45.0; First Step Diameter: 0.4650 INCHES MINIMUM AND 0.4750 INCHES MAXIMUM IN; End Diameter: 0.4290 INCHES NOMINAL IN. 16 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.