The Thread Piece,union, cataloged under National Stock Number 4730-01-299-0617, is classified within Federal Supply Class 4730 (Hose, Pipe, Tube, Lubrication, and Railing Fittings) of the Pipe, Tubing, Hose, and Fittings group. The manufacturer of record is Derbyshire Machine & Tool Co. Government technical data includes 7 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through both NSN and commercial part number lookups. 3 additional reference documents (drawings, advisory and superseded references) are recorded in the U.S. Government catalog. 4 items share a part number with this NSN in the catalog (possible match — not a government interchangeability claim). Current acquisition status: Active.
| Parameter | Value |
|---|---|
| NSN | 4730-01-299-0617 |
| Primary Part Number | 2621-791-02 PIECE 42A |
| Item Name | Thread Piece,union |
| FSC / FSG | 4730 / 47 — Hose, Pipe, Tube, Lubrication, and Railing Fittings |
| Manufacturer | Derbyshire Machine & Tool Co |
| Status | ACTIVE |
| Union End Thread Direction | RIGHT-HAND |
| Nominal Pipe Size Designation | 0.250 INCHES IN |
| End Connection Type | WELDED |
| Union End Thread Size | 1.188-12 |
| Seat Type | ANGLE |
| Union End Screw Thread Series Designator | UN |
| Material | STEEL COMP 304 |
| 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 |
|---|---|
| 2621-791-02 PIECE 42A PRIMARY | Derbyshire Machine & Tool Co (USA) |
| 2621-791-02 PIECE 42A | Naval Sea Systems Command (USA) |
| Reference | Meaning |
|---|---|
| 2621-791-02 | D/9 Drawing number reference only Naval Sea Systems Command |
| 516-5486653 F32 | C/1 Advisory reference — outside the item-of-supply concept Naval Sea Systems Command |
| 2621-791-02 PC 42A | 3/2 Design control — primary reference U.S. Government activity |
NSN 4730-01-299-0617 is a Thread Piece,union, manufactured by Derbyshire Machine & Tool Co, classified under FSC 4730, Hose, Pipe, Tube, Lubrication, and Railing Fittings. Status: active.
NSN 4730-01-299-0617 has 2 manufacturer part numbers on file: 2621-791-02 PIECE 42A (Derbyshire Machine & Tool Co), 2621-791-02 PIECE 42A (Naval Sea Systems Command).
4 possible matches (shared part number, not a government interchangeability claim): 4730-01-307-8926, 4730-01-307-8927, 4730-01-329-1590. Verify interchangeability with system specifications before substitution.
Key specifications for 2621-791-02 PIECE 42A: Union End Thread Direction: RIGHT-HAND; Nominal Pipe Size Designation: 0.250 INCHES IN; End Connection Type: WELDED; Union End Thread Size: 1.188-12. 7 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.