The Coupling,tube, cataloged under National Stock Number 4730-01-070-3393, 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 The Boeing Company Div Defense. Government technical data includes 14 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through both NSN and commercial part number lookups. 1 additional reference document (drawings, advisory and superseded references) is recorded in the U.S. Government catalog. 1 item shares a part number with this NSN in the catalog (possible match — not a government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 | 4730-01-070-3393 |
| Primary Part Number | ST7M257-550H312 |
| Item Name | Coupling,tube |
| FSC / FSG | 4730 / 47 — Hose, Pipe, Tube, Lubrication, and Railing Fittings |
| Manufacturer | The Boeing Company Div Defense |
| Status | ACTIVE |
| Surface Treatment Document and Classification | MIL-S-5002 MIL SPEC SINGLE TREATMENT RESPONSE OVERALL |
| Connection Style | PLAIN (TUBE) ALL ENDS |
| Tubing Wall Nominal Thickness for Which Designed | 0.035 INCHES ALL ENDS IN |
| Nominal Overall Length | 3.120 INCHES IN |
| Connection Type | UNTHREADED INTERNAL TUBE ALL ENDS |
| Style Designator | PLAIN W/TAPERED ENDS |
| Material Document and Classification | MIL-S-6721,TYPE 321 MIL SPEC SINGLE MATERIAL RESPONSE OR MIL-T-8808 MIL SPEC SINGLE MATERIAL RESPONSE OVERALL |
| Nominal Outside Diameter Tube Accommodated | 5.590 INCHES ALL ENDS IN |
| Operating Pressure | 45.0 POUNDS PER SQUARE INCH (PSI) MAXIMUM SINGLE RESPONSE LBS |
| Maximum Operating Temp | -65.0 FAHRENHEIT FIRST RESPONSE DEGF |
| Maximum Operating Temp | 500.0 FAHRENHEIT SECOND RESPONSE DEGF |
| Surface Treatment | PASSIVATE OVERALL |
| Media for Which Designed | AERONAUTICAL FLUID SINGLE RESPONSE |
| Material | STEEL CORROSION RESISTING OVERALL |
| 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 |
|---|---|
| ST7M257-550H312 PRIMARY | The Boeing Company Div Defense (USA) |
| 10A347-550-312 | Rsa Engineered Products, Llc Dba Rsa Engineered Products Llc (USA) |
| Reference | Meaning |
|---|---|
| ST7M257 | D/9 Drawing number reference only The Boeing Company Div Defense |
NSN 4730-01-070-3393 is a Coupling,tube, manufactured by The Boeing Company Div Defense, classified under FSC 4730, Hose, Pipe, Tube, Lubrication, and Railing Fittings. Status: active.
NSN 4730-01-070-3393 has 2 manufacturer part numbers on file: ST7M257-550H312 (The Boeing Company Div Defense), 10A347-550-312 (Rsa Engineered Products, Llc Dba Rsa Engineered Products Llc).
1 possible match (shared part number, not a government interchangeability claim): 4730-01-283-8182. Verify interchangeability with system specifications before substitution.
Key specifications for ST7M257-550H312: Surface Treatment Document and Classification: MIL-S-5002 MIL SPEC SINGLE TREATMENT RESPONSE OVERALL; Connection Style: PLAIN (TUBE) ALL ENDS; Tubing Wall Nominal Thickness for Which Designed: 0.035 INCHES ALL ENDS IN; Nominal Overall Length: 3.120 INCHES IN. 14 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.