The Elbow,tube, cataloged under National Stock Number 4730-01-137-1638, is classified within Federal Supply Class 4730 (Hose, Pipe, Tube, Lubrication, and Railing Fittings) of the Pipe, Tubing, Hose, and Fittings group. Government technical data includes 27 specifications, cited from the U.S. Government catalog. 5 additional reference documents (drawings, advisory and superseded references) are recorded in the U.S. Government catalog. 2 items share a part number with this NSN in the catalog (possible match — not a government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 | 4730-01-137-1638 |
| Item Name | Elbow,tube |
| FSC / FSG | 4730 / 47 — Hose, Pipe, Tube, Lubrication, and Railing Fittings |
| Status | ACTIVE |
| Flow Angle | 45.0 DEGREES |
| Surface Treatment Document and Classification | MIL-A-8625,TYPE 2,CLASS 1 MIL SPEC SINGLE TREATMENT RESPONSE OVERALL |
| Connection Style | SWIVEL NUT, FLARELESS (SWIVEL NUT ATTACHMENT METHOD OPTIONAL) (TUBE) FIRST END |
| Connection Style | FLARELESS (TUBE) SECOND END |
| Connection Type | THREADED EXTERNAL TUBE SECOND END |
| Connection Type | THREADED INTERNAL TUBE FIRST END |
| Material Document and Classification | QQ-A-225/6,T6,T62 OR T851 FED SPEC 2ND MATERIAL RESPONSE NUT |
| Material Document and Classification | QQ-A-367,T6 FED SPEC 1ST MATERIAL RESPONSE BODY |
| Nominal Outside Diameter Tube Accommodated | 0.375 INCHES SECOND END IN |
| Nominal Outside Diameter Tube Accommodated | 0.250 INCHES FIRST END IN |
| Operating Pressure | 3000.0 POUNDS PER SQUARE INCH (PSI) MAXIMUM SINGLE RESPONSE LBS |
| Leg Length | 0.770 INCHES NOMINAL SECOND END IN |
| Leg Length | 0.581 INCHES NOMINAL FIRST END IN |
| Nominal Thread Size | 0.562 INCHES SECOND END IN |
| Nominal Thread Size | 0.438 INCHES FIRST END IN |
| Seat Angle | 12.0 DEGREES SECOND END |
| Seat Angle | 12.0 DEGREES FIRST END |
| Specification/standard Data | 80205-NAS1761 PROFESSIONAL/INDUSTRIAL ASSOCIATION STANDARD AND 81349-MIL-F-18280 GOVERNMENT SPECIFICATION |
| Maximum Operating Temp | 275.0 FAHRENHEIT SINGLE RESPONSE DEGF |
| Surface Treatment | ANODIZE OVERALL |
| Media for Which Designed | AERONAUTICAL FLUID SINGLE RESPONSE |
| Thread Class | 3A SECOND END A |
| Thread Class | 3B FIRST END |
| Material | ALUMINUM ALLOY 2024 NUT |
| Material | ALUMINUM ALLOY 2014 BODY |
| Thread Series Designator | UNIFIED NATIONAL JOINT FINE (UNJF) FIRST END |
| Thread Series Designator | UNIFIED NATIONAL JOINT FINE (UNJF) SECOND END |
| 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 |
|---|---|
| NAS1761 | 3/1 Design control — primary reference U.S. Government activity |
| MIL-F-18280 | 5/9 Secondary reference U.S. Government activity |
| NAS1761D0406 | 3/2 Design control — primary reference U.S. Government activity |
| AS18280 | 5/1 Secondary reference Sae International Dba Sae International |
| AS18280 | 5/9 Secondary reference U.S. Government activity |
NSN 4730-01-137-1638 is a Elbow,tube, classified under FSC 4730, Hose, Pipe, Tube, Lubrication, and Railing Fittings. Status: active.
2 possible matches (shared part number, not a government interchangeability claim): 4730-01-206-4811, 4730-01-412-1133. Verify interchangeability with system specifications before substitution.
Key specifications for 4730-01-137-1638: Flow Angle: 45.0 DEGREES; Surface Treatment Document and Classification: MIL-A-8625,TYPE 2,CLASS 1 MIL SPEC SINGLE TREATMENT RESPONSE OVERALL; Connection Style: SWIVEL NUT, FLARELESS (SWIVEL NUT ATTACHMENT METHOD OPTIONAL) (TUBE) FIRST END; Connection Style: FLARELESS (TUBE) SECOND END. 27 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.