The Cock,drain, cataloged under National Stock Number 4820-01-221-8858, is classified within Federal Supply Class 4820 (Valves, Nonpowered) of the Valves group. The manufacturer of record is Frederick Custom Machining Inc. Government technical data includes 15 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through both NSN and commercial part number lookups. 2 additional reference documents (drawings, advisory and superseded references) are recorded in the U.S. Government catalog. 1 item shares a part number with this NSN in the catalog (possible match — not a government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 | 4820-01-221-8858 |
| Primary Part Number | 29959-E ITEM 309 |
| Item Name | Cock,drain |
| FSC / FSG | 4820 / 48 — Valves, Nonpowered |
| Manufacturer | Frederick Custom Machining Inc |
| Status | ACTIVE |
| Flow Control Device | PLUG |
| Connection Style | PLAIN (TUBE) ALL ENDS |
| Connection Style | PLAIN (TUBE) ALL ENDSUNABLE TO DECODE |
| Connection Type | THREADED EXTERNAL TUBE ALL ENDS |
| Connection Type | THREADED EXTERNAL TUBE ALL ENDSUNABLE TO DECODE |
| Style Designator | STRAIGHT THRU |
| Thread Direction | RIGHT-HAND ALL ENDS |
| Nominal Thread Size | 0.500 INCHES ALL ENDS IN |
| Nominal Thread Size | 0.500 INCHES ALL ENDSUNABLE TO DECODE IN |
| Thread Class | 2A ALL ENDS A |
| Material | NICKEL ALLOY BODY |
| Material | NICKEL ALLOY BODYUNABLE TO DECODE |
| Thread Series Designator | UNF ALL ENDS |
| Thread Series Designator | UNF ALL ENDSUNABLE TO DECODE |
| Valve Operation Method | MANUAL |
| Acquisition Status | ACTIVE |
| DEMIL Code | DEMIL A — No Demilitarization Required |
| Hazard | No hazard code in the DLA record (HMIC N) |
| Criticality Code | X |
| Part Number | Manufacturer |
|---|---|
| 29959-E ITEM 309 PRIMARY | Frederick Custom Machining Inc (USA) |
| Reference | Meaning |
|---|---|
| 309 | C/1 Advisory reference — outside the item-of-supply concept Frederick Custom Machining Inc |
| 29959-E | D/9 Drawing number reference only Frederick Custom Machining Inc |
NSN 4820-01-221-8858 is a Cock,drain, manufactured by Frederick Custom Machining Inc, classified under FSC 4820, Valves, Nonpowered. Status: active.
NSN 4820-01-221-8858 has 1 manufacturer part number on file: 29959-E ITEM 309 (Frederick Custom Machining Inc).
1 possible match (shared part number, not a government interchangeability claim): 4320-01-221-8950. Verify interchangeability with system specifications before substitution.
Key specifications for 29959-E ITEM 309: Flow Control Device: PLUG; Connection Style: PLAIN (TUBE) ALL ENDS; Connection Style: PLAIN (TUBE) ALL ENDSUNABLE TO DECODE; Connection Type: THREADED EXTERNAL TUBE ALL ENDS. 15 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.