Type THHN/THWN/THWN-2/T90 Wire Specifications
| Section (AWG or MCM) | Number of strands (Nos) | Insulation thickness (mils) | Jacket thickness Min. (mils) | Approx.Nominal OD (inch) |
| 14 | Solid or 7 | 15 | 4 | 0.86 |
| 12 | Solid or 7 | 15 | 4 | 1.00 |
| 10 | Solid or 7 | 20 | 4 | 1.27 |
| 8 | 7 or 19 | 30 | 5 | 1.67 |
| 6 | 7 or 19 | 30 | 5 | 1.97 |
| 4 | 7 or 19 | 40 | 6 | 2.51 |
| 2 | 7 or 19 | 40 | 6 | 2.97 |
| 1 | 7 or 19 | 50 | 7 | 3.45 |
| 1/0 | 19 | 50 | 7 | 3.76 |
| 2/0 | 19 | 50 | 7 | 4.12 |
| 3/0 | 19 | 50 | 7 | 4.52 |
| 4/0 | 19 | 50 | 7 | 4.97 |
| 250 | 19 | 60 | 8 | 5.50 |
| 350 | 37 | 60 | 8 | 6.32 |
| 400 | 37 | 60 | 8 | 6.68 |
| 450 | 37 | 60 | 8 | 7.03 |
| 500 | 37 | 60 | 8 | 7.34 |
| 750 | 61 | 70 | 9 | 8.95 |