The Elbow,tube to Boss, cataloged under National Stock Number 4730-00-904-3373, 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 Rtx Corporation Dba Pratt & Whitney Div Pratt &whitney. 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through both NSN and commercial part number lookups. 1 additional reference document (drawings, advisory and superseded references) is recorded in the U.S. Government catalog. Current acquisition status: Active.
| Parameter | Value |
|---|---|
| NSN | 4730-00-904-3373 |
| Primary Part Number | 520399 |
| Item Name | Elbow,tube to Boss |
| FSC / FSG | 4730 / 47 — Hose, Pipe, Tube, Lubrication, and Railing Fittings |
| Manufacturer | Rtx Corporation Dba Pratt & Whitney Div Pratt &whitney |
| Status | ACTIVE |
| Flow Angle | 90.0 DEGREES |
| Connection Style | FLARED (TUBE) FIRST END |
| Connection Style | DOUBLE THREADED SECTION W/ GASKET AND LOCKNUT SEALING (BOSS) SECOND END |
| Connection Type | THREADED EXTERNAL TUBE FIRST END |
| Connection Type | THREADED EXTERNAL BOSS SECOND END BULKHEAD |
| Nominal Outside Diameter Tube Accommodated | 0.375 INCHES FIRST END IN |
| Leg Length | 0.850 INCHES MINIMUM AND 0.870 INCHES MAXIMUM FIRST END IN |
| Leg Length | 1.234 INCHES MINIMUM AND 1.270 INCHES MAXIMUM SECOND END IN |
| Nominal Thread Size | 0.562 INCHES FIRST END IN |
| Nominal Thread Size | 0.438 INCHES SECOND END BULKHEAD IN |
| Seat Angle | 37.0 DEGREES FIRST END |
| Surface Treatment | PASSIVATE OVERALL |
| Media for Which Designed | HYDRAULIC FLUID FIRST RESPONSE |
| Media for Which Designed | AERONAUTICAL FLUID SECOND RESPONSE |
| Thread Class | 3A SECOND END BULKHEAD A |
| Thread Class | 3A ALL ENDS A |
| Material | STEEL CORROSION RESISTING OVERALL |
| Thread Series Designator | UNF ALL ENDS |
| Thread Series Designator | UNF SECOND END BULKHEAD |
| 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 |
|---|---|
| 520399 PRIMARY | Rtx Corporation Dba Pratt & Whitney Div Pratt &whitney (USA) |
| Reference | Meaning |
|---|---|
| 520399 | 5/9 Secondary reference Turbo Power & Marine System Inc Sub of United Technologies Corp |
NSN 4730-00-904-3373 is a Elbow,tube to Boss, manufactured by Rtx Corporation Dba Pratt & Whitney Div Pratt &whitney, classified under FSC 4730, Hose, Pipe, Tube, Lubrication, and Railing Fittings. Status: active.
NSN 4730-00-904-3373 has 1 manufacturer part number on file: 520399 (Rtx Corporation Dba Pratt & Whitney Div Pratt &whitney).
Key specifications for 520399: Flow Angle: 90.0 DEGREES; Connection Style: FLARED (TUBE) FIRST END; Connection Style: DOUBLE THREADED SECTION W/ GASKET AND LOCKNUT SEALING (BOSS) SECOND END; Connection Type: THREADED EXTERNAL TUBE FIRST 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.