The Hose,air Duct, cataloged under National Stock Number 4720-01-252-4656, is classified within Federal Supply Class 4720 (Hose and Flexible Tubing) of the Pipe, Tubing, Hose, and Fittings group. Government technical data includes 19 specifications, cited from the U.S. Government catalog. 3 additional reference documents (drawings, advisory and superseded references) are recorded in the U.S. Government catalog. Current acquisition status: Active.
| Parameter | Value |
|---|---|
| NSN | 4720-01-252-4656 |
| Item Name | Hose,air Duct |
| FSC / FSG | 4720 / 47 — Hose and Flexible Tubing |
| Status | ACTIVE |
| Measuring Method and Length | 4.000 INCHES NOMINAL OVERALL IN |
| Minimum Inside Bending Radius | 2.000 INCHES IN |
| Connection Style | ROUND FIRST END |
| Connection Type | SOFT FIRST END |
| Style Designator | FULLY CONVOLUTED W/ WIRE RINGS BETWEEN CONVOLUTIONS |
| Material Document and Classification | MIL-Y-1140 MIL SPEC SINGLE MATERIAL RESPONSE REINFORCING CORD |
| Cross-Sectional Shape Style | ROUND |
| Wall Thickness | 0.020 INCHES MINIMUM AND 0.080 INCHES MAXIMUM IN |
| Operating Pressure | 4.0 POUNDS PER SQUARE INCH (PSI) MAXIMUM LBS |
| Specification/standard Data | 81205-BACD40B MANUFACTURERS STANDARD |
| Nondefinitive Spec/std Data | 2 CLASS AND 2 TYPE AND B GRADE |
| Inside Diameter | 2.000 INCHES NOMINAL FIRST END IN |
| End Overall Length | 1.250 INCHES NOMINAL FIRST END IN |
| End Inside Diameter | 2.000 INCHES NOMINAL FIRST END IN |
| Test Data Document | 81205-BMS 8-17 SPECIFICATION (INCLUDES ENGINEERING TYPE BULLETINS, BROCHURES,ETC., THAT REFLECT SPECIFICATION TYPE DATA IN SPECIFICATION FORMAT; EXCLUDES COMMERCIAL CATALOGS, INDUSTRY DIRECTORIES, AND SIMILAR TRADE PUBLICATIONS, REFLECTING GENERAL TYPE DATA ON CERTAIN ENVIRONMENTAL AND PERFORMANCE REQUIREMENTS AND TEST CONDITIONS THAT ARE SHOWN AS "TYPICAL", "AVERAGE", "NOMINAL", ETC.). |
| Material | COTTON AND FIBERGLASS THIRD PLY |
| Material | FIBERGLASS REINFORCING CORD |
| Material | STEEL SECOND PLY |
| Material | COTTON AND FIBERGLASS FIRST PLY |
| 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 |
|---|---|
| BACD40B | D/9 Drawing number reference only U.S. Government activity |
| BACD40B8-6-5-11 | 5/9 Secondary reference U.S. Government activity |
| BACD40B008-006-5-11 | 3/2 Design control — primary reference U.S. Government activity |
NSN 4720-01-252-4656 is a Hose,air Duct, classified under FSC 4720, Hose and Flexible Tubing. Status: active.
Key specifications for 4720-01-252-4656: Measuring Method and Length: 4.000 INCHES NOMINAL OVERALL IN; Minimum Inside Bending Radius: 2.000 INCHES IN; Connection Style: ROUND FIRST END; Connection Type: SOFT 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.