The Reducer,tube, cataloged under National Stock Number 4730-01-159-8956, 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 17 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through both NSN and commercial part number lookups. 7 additional reference documents (drawings, advisory and superseded references) are recorded in the U.S. Government catalog. Current acquisition status: Active.
| Parameter | Value |
|---|---|
| NSN | 4730-01-159-8956 |
| Primary Part Number | 7M637NB-D6-4 |
| Item Name | Reducer,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-C-83488,CL 3,TY 2 MIL SPEC SINGLE TREATMENT RESPONSE OVERALL |
| Connection Style | PLAIN (TUBE) SECOND END |
| Connection Style | FLARED (TUBE) FIRST END |
| Nominal Overall Length | 0.969 INCHES IN |
| Connection Type | THREADED EXTERNAL TUBE FIRST END |
| Connection Type | UNTHREADED EXTERNAL TUBE SECOND END |
| Material Document and Classification | QQ-A-225/4 FED SPEC 1ST MATERIAL RESPONSE OR QQ-A-225/6 FED SPEC 2ND MATERIAL RESPONSE OVERALL |
| Nominal Outside Diameter Tube Accommodated | 0.375 INCHES SECOND END IN |
| Nominal Outside Diameter Tube Accommodated | 0.250 INCHES FIRST END IN |
| Reduced Passage Nominal Inside Diameter | 0.172 INCHES FIRST END IN |
| Nominal Thread Size | 0.438 INCHES FIRST END IN |
| Seat Angle | 37.0 DEGREES FIRST END |
| Surface Treatment | ALUMINUM OVERALL |
| Thread Class | 3A FIRST END A |
| Material | ALUMINUM ALLOY OVERALL |
| Thread Series Designator | UNF FIRST END |
| 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 |
|---|---|
| 7M637NB-D6-4 PRIMARY | The Boeing Company Div Defense (USA) |
| Reference | Meaning |
|---|---|
| 10108820 | 6/9 Informative reference only Nimikkeistokeskus Ncb Finland |
| 7M637NB-D6-4 | 5/1 Secondary reference Allan Aircraft Supply Co., Llc Dba Allan Aircraft Supply |
| 7M637NB-D6-4 | 5/9 Secondary reference Faber Enterprises, Inc. Div Faber Enterprise Inc |
| 7M637NB-D6-4 | 5/9 Secondary reference Designed Metal Connections Inc Dba Permaswage Usa Div Permaswage, a Pcc Company |
| 7M637NB-D6-4 | 5/1 Secondary reference Nelson Aero Space, Inc. |
| 7M637NB-D6-4 | 5/1 Secondary reference Sps Technologies, Llc Dba Airdrome Precision Components |
| 7M637 | D/9 Drawing number reference only The Boeing Company Div Defense |
NSN 4730-01-159-8956 is a Reducer,tube, manufactured by The Boeing Company Div Defense, classified under FSC 4730, Hose, Pipe, Tube, Lubrication, and Railing Fittings. Status: active.
NSN 4730-01-159-8956 has 1 manufacturer part number on file: 7M637NB-D6-4 (The Boeing Company Div Defense).
Key specifications for 7M637NB-D6-4: Surface Treatment Document and Classification: MIL-C-83488,CL 3,TY 2 MIL SPEC SINGLE TREATMENT RESPONSE OVERALL; Connection Style: PLAIN (TUBE) SECOND END; Connection Style: FLARED (TUBE) FIRST END; Nominal Overall Length: 0.969 INCHES IN. 17 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.