Ducts - Sheet Metal Gauges
Thickness of sheet metal used in ductwork.
Ductwork sheet metal gauges:
| Comments | Sheet Metal Gauge | Sheet Thickness (inches) |
|---|---|---|
| Welded Ductwork | 0 | 0.3120 |
| 1 | 0.2810 | |
| 2 | 0.2650 | |
| 3 | 0.2500 | |
| 4 | 0.2340 | |
| 5 | 0.2187 | |
| 6 | 0.2030 | |
| 7 | 0.1875 | |
| 8 | 0.1720 | |
| 9 | 0.1560 | |
| 10 | 0.1400 | |
| 11 | 0.1250 | |
| 12 | 0.1090 | |
| 13 | 0.0937 | |
| 14 | 0.0780 | |
| 15 | 0.0700 | |
| SMACNA1) Ductwork | 16 | 0.0625 |
| 17 | 0.0560 | |
| 18 | 0.0500 | |
| 19 | 0.0437 | |
| 20 | 0.0375 | |
| 21 | 0.0343 | |
| 22 | 0.0312 | |
| 23 | 0.0280 | |
| 24 | 0.0250 | |
| 25 | 0.0218 | |
| 26 | 0.0187 | |
| Not Suited for Ductwork | 27 | 0.0170 |
| 28 | 0.0156 | |
| 29 | 0.0140 | |
| 30 | 0.0125 | |
| 31 | 0.0109 | |
| 32 | 0.0100 | |
| 33 | 0.0093 | |
| 34 | 0.0085 | |
| 35 | 0.0078 | |
| 36 | 0.0070 |
- 1 inch = 25.4 mm
Recommended Gages for Circular Ducts for Heating and General Ventilation Work
| Diameter (inches) | Gauge |
|---|---|
| 6 - 19 | 26 |
| 20 - 29 | 24 |
| 30 - 39 | 22 |
| 40 - 49 | 20 |
| > 49 | 18 |
Recommended Gages for Circular Ducts for Industrial Exhaust Work
| Diameter (inches) | Gauge |
|---|---|
| < 9 | 24 |
| 9 - 14 | 22 |
| 15 - 20 | 20 |
| 21 - 30 | 18 |
| > 30 | 16 |
