The Seat,valve, cataloged under National Stock Number 4820-00-858-1653, is classified within Federal Supply Class 4820 (Valves, Nonpowered) of the Valves group. Government technical data includes 14 specifications, cited from the U.S. Government catalog. 2 additional reference documents (drawings, advisory and superseded references) are recorded in the U.S. Government catalog. Current acquisition status: Active.
| Parameter | Value |
|---|---|
| NSN | 4820-00-858-1653 |
| Item Name | Seat,valve |
| FSC / FSG | 4820 / 48 — Valves, Nonpowered |
| Status | ACTIVE |
| Body Outside Diameter | 0.625 INCHES NOMINAL IN |
| Thread Length | 0.360 INCHES NOMINAL FIRST THREADED PORTION IN |
| Thread Length | 0.421 INCHES NOMINAL SECOND THREADED PORTION IN |
| Seal Accommodation Type | GROOVED |
| Hardness Rating | 48.0 ROCKWELL C MINIMUM AND 52.0 ROCKWELL C MAXIMUM OVERALL |
| Nominal Thread Size | 0.875 INCHES FIRST THREADED PORTION IN |
| Nominal Thread Size | 0.875 INCHES SECOND THREADED PORTION IN |
| Thread Class | 3A FIRST THREADED PORTION A |
| Thread Class | 3A SECOND THREADED PORTION A |
| Material | STEEL COMP 52100 OVERALL |
| Seat Angle in Deg | 15.000 NOMINAL |
| Thread Series Designator | UNF FIRST THREADED PORTION |
| Thread Series Designator | UNF SECOND THREADED PORTION |
| Seating Surface Shape | ANGULAR |
| Acquisition Status | ACTIVE |
| DEMIL Code | DEMIL A — No Demilitarization Required |
| Hazard | No hazard code in the DLA record (HMIC N) |
| Criticality Code | X |
| Reference | Meaning |
|---|---|
| 2356975 | 3/2 Design control — primary reference U.S. Government activity |
| 2356975 | 5/9 Secondary reference The Boeing Company |
NSN 4820-00-858-1653 is a Seat,valve, classified under FSC 4820, Valves, Nonpowered. Status: active.
Key specifications for 4820-00-858-1653: Overall Height: 2.459 INCHES NOMINAL IN; Body Outside Diameter: 0.625 INCHES NOMINAL IN; Thread Length: 0.360 INCHES NOMINAL FIRST THREADED PORTION IN; Thread Length: 0.421 INCHES NOMINAL SECOND THREADED PORTION IN. 14 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.