The Union,pipe, cataloged under National Stock Number 4730-01-127-7738, 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 Guill Tool & Engineering Co Inc Div Guill Defense. Government technical data includes 19 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through both NSN and commercial part number lookups. 3 additional reference documents (drawings, advisory and superseded references) are recorded in the U.S. Government catalog. Current acquisition status: Active.
| Parameter | Value |
|---|---|
| NSN | 4730-01-127-7738 |
| Primary Part Number | 2621-791-03ASSY81 |
| Item Name | Union,pipe |
| FSC / FSG | 4730 / 47 — Hose, Pipe, Tube, Lubrication, and Railing Fittings |
| Manufacturer | Guill Tool & Engineering Co Inc Div Guill Defense |
| Status | ACTIVE |
| Furnished Items and Quantity | 1 PREFORMED PACKING |
| Nominal Pipe Size Accommodated | 0.500 INCHES SECOND END IN |
| Nominal Pipe Size Accommodated | 0.500 INCHES FIRST END IN |
| Connection Style | PLAIN BEVELED (PIPE) SECOND END |
| Coupling Flange Shape | HEXAGON |
| Nominal Overall Length | 6.434 INCHES IN |
| Connection Type | UNTHREADED INTERNAL PIPE FIRST END |
| Connection Type | UNTHREADED EXTERNAL PIPE SECOND END |
| Style Designator | UNTHREADED |
| Material Document and Classification | QQ-S-763,CL 304,COND A FED SPEC SINGLE MATERIAL RESPONSE TAILPIECE |
| Material Document and Classification | QQ-N-281 FED SPEC SINGLE MATERIAL RESPONSE NUT |
| Material Document and Classification | QQ-S-763,CL 304,COND A FED SPEC SINGLE MATERIAL RESPONSE THREAD PIECE |
| Operating Pressure | 3000.0 POUNDS PER SQUARE INCH (PSI) MAXIMUM SINGLE RESPONSE LBS |
| Seat Type | GASKET |
| Pipe Wall Thickness Designation for Which Designed | SCHEDULE 80S ALL ENDS |
| Material | NICKEL ALLOY NUT |
| Material | STEEL COMP 304 THREAD PIECE |
| Material | STEEL COMP 304 TAILPIECE |
| Reducer Type | CONCENTRIC |
| 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 |
|---|---|
| 2621-791-03ASSY81 PRIMARY | Guill Tool & Engineering Co Inc Div Guill Defense (USA) |
| Reference | Meaning |
|---|---|
| 4684589 F23 | 5/2 Secondary reference U.S. Government activity |
| 2621-791-03 | D/9 Drawing number reference only U.S. Government activity |
| 2621-791-03ASSY81 | 3/2 Design control — primary reference U.S. Government activity |
NSN 4730-01-127-7738 is a Union,pipe, manufactured by Guill Tool & Engineering Co Inc Div Guill Defense, classified under FSC 4730, Hose, Pipe, Tube, Lubrication, and Railing Fittings. Status: active.
NSN 4730-01-127-7738 has 1 manufacturer part number on file: 2621-791-03ASSY81 (Guill Tool & Engineering Co Inc Div Guill Defense).
Key specifications for 2621-791-03ASSY81: Furnished Items and Quantity: 1 PREFORMED PACKING; Nominal Pipe Size Accommodated: 0.500 INCHES SECOND END IN; Nominal Pipe Size Accommodated: 0.500 INCHES FIRST END IN; Connection Style: PLAIN BEVELED (PIPE) SECOND END. 19 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.