The Seat,helical Compression Spring, cataloged under National Stock Number 5340-01-491-4354, is classified within Federal Supply Class 5340 (Hardware, Commercial) of the Hardware and Abrasives group. The manufacturer of record is Naval Sea Systems Command. Government technical data includes 11 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through both NSN and commercial part number lookups. 2 additional reference documents (drawings, advisory and superseded references) are recorded in the U.S. Government catalog. 6 items share a part number with this NSN in the catalog (possible match — not a government interchangeability claim). Current acquisition status: Active. Unit of issue: EA.
| Parameter | Value |
|---|---|
| NSN | 5340-01-491-4354 |
| Primary Part Number | 124-7120998 PC 8-82 |
| Item Name | Seat,helical Compression Spring |
| FSC / FSG | 5340 / 53 — Hardware, Commercial |
| Manufacturer | Naval Sea Systems Command |
| Status | ACTIVE |
| First Step Diameter | 10.4380 INCHES NOMINAL IN |
| End Diameter | 7.8120 INCHES NOMINAL IN |
| Second End Diameter | 7.8120 INCHES NOMINAL IN |
| Distance From End to First Step | 1.5000 INCHES NOMINAL IN |
| Design Type | SPLIT |
| Style Designator | SEAT |
| Counterbore Length | 1.5000 INCHES NOMINAL IN |
| Counterbore Diameter | 6.0000 INCHES NOMINAL IN |
| First Step Length | 0.6250 INCHES NOMINAL IN |
| Bore Diameter | 6.0000 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 |
|---|---|
| 124-7120998 PC 8-82 PRIMARY | Naval Sea Systems Command (USA) |
| Reference | Meaning |
|---|---|
| 7120998 | D/9 Drawing number reference only Naval Sea Systems Command |
| 124-7120998 PC | C/1 Advisory reference — outside the item-of-supply concept Naval Sea Systems Command |
NSN 5340-01-491-4354 is a Seat,helical Compression Spring, manufactured by Naval Sea Systems Command, classified under FSC 5340, Hardware, Commercial. Status: active.
NSN 5340-01-491-4354 has 1 manufacturer part number on file: 124-7120998 PC 8-82 (Naval Sea Systems Command).
6 possible matches (shared part number, not a government interchangeability claim): 3040-01-491-7892, 5340-01-492-0435, 5340-01-492-0438. Verify interchangeability with system specifications before substitution.
Key specifications for 124-7120998 PC 8-82: Overall Height: 3.6250 INCHES NOMINAL IN; First Step Diameter: 10.4380 INCHES NOMINAL IN; End Diameter: 7.8120 INCHES NOMINAL IN; Second End Diameter: 7.8120 INCHES NOMINAL IN. 11 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.