The Seat,helical Compression Spring, cataloged under National Stock Number 5340-01-209-8326, is classified within Federal Supply Class 5340 (Hardware, Commercial) of the Hardware and Abrasives group. The manufacturer of record is Dover Pumps & Process Solutions Segment Inc Dba Blackmer Div Blackmer. Government technical data includes 3 specifications, cited from the U.S. Government catalog. The record lists 2 manufacturer part numbers 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 | 5340-01-209-8326 |
| Primary Part Number | 421806 |
| Item Name | Seat,helical Compression Spring |
| FSC / FSG | 5340 / 53 — Hardware, Commercial |
| Manufacturer | Dover Pumps & Process Solutions Segment Inc Dba Blackmer Div Blackmer |
| Status | ACTIVE |
| Design Type | SOLID OR SPLIT |
| Material Document and Classification | QQ-B-637 FED SPEC 1ST MATERIAL RESPONSE OR SAE CA 360, COMP 22 ASSN STD 2ND MATERIAL RESPONSE |
| Material | COPPER ALLOY 462 OR COPPER ALLOY 464 OR COPPER ALLOY 482 OR COPPER ALLOY 485 OR COPPER ALLOY 360 |
| 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 |
|---|---|
| 421806 PRIMARY | Dover Pumps & Process Solutions Segment Inc Dba Blackmer Div Blackmer (USA) |
| E-3947 PIECE7 | Dover Pumps & Process Solutions Segment Inc Dba Blackmer Div Blackmer (USA) |
NSN 5340-01-209-8326 is a Seat,helical Compression Spring, manufactured by Dover Pumps & Process Solutions Segment Inc Dba Blackmer Div Blackmer, classified under FSC 5340, Hardware, Commercial. Status: active.
NSN 5340-01-209-8326 has 2 manufacturer part numbers on file: 421806 (Dover Pumps & Process Solutions Segment Inc Dba Blackmer Div Blackmer), E-3947 PIECE7 (Dover Pumps & Process Solutions Segment Inc Dba Blackmer Div Blackmer).
1 possible match (shared part number, not a government interchangeability claim): 5340-01-568-9296. Verify interchangeability with system specifications before substitution.
Key specifications for 421806: Design Type: SOLID OR SPLIT; Material Document and Classification: QQ-B-637 FED SPEC 1ST MATERIAL RESPONSE OR SAE CA 360, COMP 22 ASSN STD 2ND MATERIAL RESPONSE; Material: COPPER ALLOY 462 OR COPPER ALLOY 464 OR COPPER ALLOY 482 OR COPPER ALLOY 485 OR COPPER ALLOY 360. 3 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.