The Retainer,helical Compression Spr, cataloged under National Stock Number 5340-00-478-2640, is classified within Federal Supply Class 5340 (Hardware, Commercial) of the Hardware and Abrasives group. The manufacturer of record is Hamilton Sundstrand Corporation Dba Collins Aerospace. 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 item shares 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 | 5340-00-478-2640 |
| Primary Part Number | 740238-2 |
| Item Name | Retainer,helical Compression Spr |
| FSC / FSG | 5340 / 53 — Hardware, Commercial |
| Manufacturer | Hamilton Sundstrand Corporation Dba Collins Aerospace |
| Status | ACTIVE |
| Material Hardness Rating | 31.0 ROCKWELL C MINIMUM AND 39.0 ROCKWELL C MAXIMUM |
| Body Outside Diameter | 0.4220 INCHES MINIMUM AND 0.4260 INCHES MAXIMUM IN |
| Style Designator | IRREGULAR |
| Material Document and Classification | HS 279 OR H1075,FSCM 73030 MFR REF SINGLE MATERIAL RESPONSE |
| Body Inside Diameter | 0.3760 INCHES MINIMUM AND 0.3780 INCHES MAXIMUM IN |
| Casehardening Indicator | NOT CASEHARDENED |
| 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 |
|---|---|
| 740238-2 PRIMARY | Hamilton Sundstrand Corporation Dba Collins Aerospace (USA) |
NSN 5340-00-478-2640 is a Retainer,helical Compression Spr, manufactured by Hamilton Sundstrand Corporation Dba Collins Aerospace, classified under FSC 5340, Hardware, Commercial. Status: active.
NSN 5340-00-478-2640 has 1 manufacturer part number on file: 740238-2 (Hamilton Sundstrand Corporation Dba Collins Aerospace).
1 possible match (shared part number, not a government interchangeability claim): 4730-00-529-3034. Verify interchangeability with system specifications before substitution.
Key specifications for 740238-2: Overall Height: 0.5200 INCHES NOMINAL IN; Material Hardness Rating: 31.0 ROCKWELL C MINIMUM AND 39.0 ROCKWELL C MAXIMUM; Body Outside Diameter: 0.4220 INCHES MINIMUM AND 0.4260 INCHES MAXIMUM IN; Style Designator: IRREGULAR. 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.