The Lower Locking Ring, cataloged under National Stock Number 2040-01-361-9769, is classified within Federal Supply Class 2040 (Marine Hardware and Hull Items) of the Ship and Marine Equipment group. The manufacturer of record is Naval Sea Systems Command. The record lists 1 manufacturer part number for this item, enabling identification through both NSN and commercial part number lookups. 5 additional reference documents (drawings, advisory and superseded references) are recorded in the U.S. Government catalog. 2 items share a part number with this NSN in the catalog (possible match — not a government interchangeability claim). Current acquisition status: Active.
| Item Name | Lower Locking Ring |
| FSC / FSG | 2040 — Marine Hardware and Hull Items (FSG 20) |
| Manufacturers | Naval Sea Systems Command (CAGE 53711) |
| Parameter | Value |
|---|---|
| NSN | 2040-01-361-9769 |
| Primary Part Number | 400-6640203 ITEM 23 |
| Item Name | Lower Locking Ring |
| FSC / FSG | 2040 / 20 — Marine Hardware and Hull Items |
| Manufacturer | Naval Sea Systems Command |
| Status | ACTIVE |
| Acquisition Status | ACTIVE |
| DEMIL Code | DEMIL A — No Demilitarization Required |
| Hazard | No hazard code in the DLA record (HMIC N) |
| Part Number | Manufacturer |
|---|---|
| 400-6640203 ITEM 23 PRIMARY | Naval Sea Systems Command (USA) |
| Reference | Meaning |
|---|---|
| A9920316 | 5/9 Secondary reference Naval Ship Engineering Center Philadelphia Division Submarine Antenna Quality Assurance |
| 6640203-23 | C/1 Advisory reference — outside the item-of-supply concept Naval Sea Systems Command |
| F8820223 | 5/9 Secondary reference Naval Ship Engineering Center Philadelphia Division Submarine Antenna Quality Assurance |
| 6640225 | 5/1 Secondary reference Naval Sea Systems Command |
| 6640225 ITEM 21 | 5/9 Secondary reference Naval Sea Systems Command |
NSN 2040-01-361-9769 is a Lower Locking Ring, manufactured by Naval Sea Systems Command, classified under FSC 2040, Marine Hardware and Hull Items. Status: active.
NSN 2040-01-361-9769 has 1 manufacturer part number on file: 400-6640203 ITEM 23 (Naval Sea Systems Command).
2 possible matches (shared part number, not a government interchangeability claim): 5340-01-361-9770, 2040-01-363-8287. Verify interchangeability with system specifications before substitution.
No hazard code in the DLA record (HMIC N). 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.