The Plug,machine Thread, cataloged under National Stock Number 5365-01-545-4121, is classified within Federal Supply Class 5365 (Bushings, Rings, Shims, and Spacers) of the Hardware and Abrasives group. The manufacturer of record is Naval Inventory Control Point Mechanicsburg. Government technical data includes 2 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through both NSN and commercial part number lookups. 3 additional reference documents (drawings, advisory and superseded references) are recorded in the U.S. Government catalog. 1 item shares a part number with this NSN in the catalog (possible match — not a government interchangeability claim). Current acquisition status: Active.
| Parameter | Value |
|---|---|
| NSN | 5365-01-545-4121 |
| Primary Part Number | MS51840-23L1 |
| Item Name | Plug,machine Thread |
| FSC / FSG | 5365 / 53 — Bushings, Rings, Shims, and Spacers |
| Manufacturer | Naval Inventory Control Point Mechanicsburg |
| Status | ACTIVE |
| Criticality Code Justification | ZZZY |
| Reference Number Differentiating Characteristics | MATERIAL CONTROLLED IAW NAVSEA 0948-LP-045-7010 MATERIAL CONTROL STANDARD FOR LEVEL I ITEMS |
| Acquisition Status | ACTIVE |
| DEMIL Code | DEMIL A — No Demilitarization Required |
| Hazard | No hazard code in the DLA record (HMIC N) |
| Criticality Code | S |
| Part Number | Manufacturer |
|---|---|
| MS51840-23L1 | Naval Inventory Control Point Mechanicsburg (USA) |
| D1234SW ITEM 22L1 | Naval Inventory Control Point Mechanicsburg (USA) |
| Reference | Meaning |
|---|---|
| D50-0050 ITEM 26 | 5/9 Secondary reference Danco Valve Company |
| MS51840-23 | 3/9 Design control — primary reference Danco Valve Company |
| D1234SW ITEM 22 | 5/9 Secondary reference Danco Valve Company |
NSN 5365-01-545-4121 is a Plug,machine Thread, manufactured by Naval Inventory Control Point Mechanicsburg, classified under FSC 5365, Bushings, Rings, Shims, and Spacers. Status: active.
NSN 5365-01-545-4121 has 2 manufacturer part numbers on file: MS51840-23L1 (Naval Inventory Control Point Mechanicsburg), D1234SW ITEM 22L1 (Naval Inventory Control Point Mechanicsburg).
1 possible match (shared part number, not a government interchangeability claim): 5365-01-616-1167. Verify interchangeability with system specifications before substitution.
Key specifications for MS51840-23L1: Criticality Code Justification: ZZZY; End Item Identification: .500IPS X .750IPS RELIEFE VALVE; Reference Number Differentiating Characteristics: MATERIAL CONTROLLED IAW NAVSEA 0948-LP-045-7010 MATERIAL CONTROL STANDARD FOR LEVEL I ITEMS. 2 specifications are documented in the U.S. Government catalog.
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.