The Hose,air Duct, cataloged under National Stock Number 4720-01-421-5254, is classified within Federal Supply Class 4720 (Hose and Flexible Tubing) of the Pipe, Tubing, Hose, and Fittings group. The manufacturer of record is The Boeing Company Div Legacy Am&m. 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through both NSN and commercial part number lookups. 1 additional reference document (drawings, advisory and superseded references) is recorded in the U.S. Government catalog. 1 item shares a part number with this NSN in the catalog (possible match — not a government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 | 4720-01-421-5254 |
| Primary Part Number | 4D3-0112-0408 |
| Item Name | Hose,air Duct |
| FSC / FSG | 4720 / 47 — Hose and Flexible Tubing |
| Manufacturer | The Boeing Company Div Legacy Am&m |
| Status | ACTIVE |
| Measuring Method and Length | 4.500 INCHES NOMINAL OVERALL IN |
| Connection Style | ROUND BOTH ENDS |
| Connection Type | PREFORMED BOTH ENDS |
| Style Designator | SLEEVE SECTION |
| Material Document and Classification | ECC-122 MFR REF SINGLE MATERIAL RESPONSE FIRST PLY |
| Material Document and Classification | ECC-128 MFR REF SINGLE MATERIAL RESPONSE SECOND PLY |
| Material Document and Classification | ECC-164 MFR REF 1ST MATERIAL RESPONSE AND ZZ-R-765,CL3A FED SPEC 2ND MATERIAL RESPONSE FOURTH PLY |
| Material Document and Classification | ECC-164 MFR REF 1ST MATERIAL RESPONSE AND ZZ-R-765,CL3A FED SPEC 2ND MATERIAL RESPONSE THIRD PLY |
| Cross-Sectional Shape Style | ROUND |
| Operating Pressure | 65.0 POUNDS PER SQUARE INCH (PSI) MAXIMUM LBS |
| Inside Diameter | 1.750 INCHES NOMINAL FIRST END IN |
| End Overall Length | 0.875 INCHES NOMINAL BOTH ENDS IN |
| End Inside Diameter | 1.750 INCHES NOMINAL BOTH ENDS IN |
| Material | FIBERGLASS AND RUBBER SILICONE CLASS Q THIRD PLY |
| Material | FIBERGLASS SECOND PLY |
| Material | FIBERGLASS FIRST PLY |
| Material | FIBERGLASS AND RUBBER SILICONE CLASS Q FOURTH PLY |
| 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 |
|---|---|
| 4D3-0112-0408 PRIMARY | The Boeing Company Div Legacy Am&m (USA) |
| Reference | Meaning |
|---|---|
| 4D3 | D/9 Drawing number reference only The Boeing Company Div Legacy Am&m |
NSN 4720-01-421-5254 is a Hose,air Duct, manufactured by The Boeing Company Div Legacy Am&m, classified under FSC 4720, Hose and Flexible Tubing. Status: active.
NSN 4720-01-421-5254 has 1 manufacturer part number on file: 4D3-0112-0408 (The Boeing Company Div Legacy Am&m).
1 possible match (shared part number, not a government interchangeability claim): 4720-01-535-4050. Verify interchangeability with system specifications before substitution.
Key specifications for 4D3-0112-0408: Measuring Method and Length: 4.500 INCHES NOMINAL OVERALL IN; Connection Style: ROUND BOTH ENDS; Connection Type: PREFORMED BOTH ENDS; Style Designator: SLEEVE SECTION. 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.