The Seat,helical Compression Spring, cataloged under National Stock Number 5340-01-058-4890, is classified within Federal Supply Class 5340 (Hardware, Commercial) of the Hardware and Abrasives group. The manufacturer of record is Itt Aerospace Controls Llc Dba Itt Aerospace Controls Unit S. 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 | 5340-01-058-4890 |
| Primary Part Number | 42540A |
| Item Name | Seat,helical Compression Spring |
| FSC / FSG | 5340 / 53 — Hardware, Commercial |
| Manufacturer | Itt Aerospace Controls Llc Dba Itt Aerospace Controls Unit S |
| Status | ACTIVE |
| First Step Diameter | 0.7400 INCHES MINIMUM AND 0.7600 INCHES MAXIMUM IN |
| Surface Treatment Document and Classification | QQ-P-35 FED SPEC SINGLE TREATMENT RESPONSE |
| Distance From End to First Step | 0.2800 INCHES NOMINAL IN |
| Design Type | SOLID |
| Style Designator | SEAT |
| Material Document and Classification | AMS 5643 ASSN STD SINGLE MATERIAL RESPONSE |
| Counterbore Length | 0.1350 INCHES NOMINAL IN |
| Counterbore Diameter | 0.3700 INCHES MINIMUM AND 0.3800 INCHES MAXIMUM IN |
| Surface Treatment | PASSIVATE |
| Material | STEEL COMP 630 |
| 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 |
|---|---|
| 42540A PRIMARY | Itt Aerospace Controls Llc Dba Itt Aerospace Controls Unit S (USA) |
NSN 5340-01-058-4890 is a Seat,helical Compression Spring, manufactured by Itt Aerospace Controls Llc Dba Itt Aerospace Controls Unit S, classified under FSC 5340, Hardware, Commercial. Status: active.
NSN 5340-01-058-4890 has 1 manufacturer part number on file: 42540A (Itt Aerospace Controls Llc Dba Itt Aerospace Controls Unit S).
Key specifications for 42540A: Overall Height: 0.3500 INCHES NOMINAL IN; First Step Diameter: 0.7400 INCHES MINIMUM AND 0.7600 INCHES MAXIMUM IN; Surface Treatment Document and Classification: QQ-P-35 FED SPEC SINGLE TREATMENT RESPONSE; Distance From End to First Step: 0.2800 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.