31 AWG (American Wire Gauge) wire specifications: 0.2268 mm diameter, 0.0404 mm² area. Resistance, weight, and common uses.
| Diameter | 0.2268 mm · 0.008928" · 8.93 mils |
| Cross-sectional area | 0.0404 mm² · 80 circular mils |
| Resistance (copper, 20°C) | 426.8788 Ω/km · 130.1127 Ω/1000ft |
| Resistance (aluminum, 20°C) | 699.8 Ω/km · 213.3 Ω/1000ft |
| Ampacity — copper 60°C | — A |
| Ampacity — copper 75°C | — A |
| Ampacity — copper 90°C | — A |
| Ampacity — aluminum 75°C | — A |
| Weight (copper) | 0.362 kg/km · 0.243 lbs/1000ft |
| Weight (aluminum) | 0.109 kg/km · 0.073 lbs/1000ft |
| Closest IEC 60228 size | 0.0404 mm² actual — smaller than 0.5 mm², the smallest IEC 60228 size |
| Skin depth at 60 Hz | 8.531 mm |
| Type | Temperature | Description |
|---|---|---|
| PVC | 60-105°C | General purpose insulation |
| Teflon (PTFE) | 200°C | High temperature applications |
| Silicone | 200°C | Flexible, high temperature |
| Enamel | 155-220°C | Magnet wire coating |
31 AWG wire (0.2268 mm diameter) is used in magnet wire for small coil windings, miniature transformers, and electromagnetic sensor coils. It appears in RFID tag antennas, small solenoids, and precision instrument windings. At this size, it is typically sold as enameled magnet wire rather than insulated hookup wire.
31 AWG wire has a diameter of 0.2268 mm (226.8 µm), which is roughly 3.2× the thickness of a human hair (about 0.07 mm). Its cross-sectional area is just 0.040386 mm². At this size, the wire is too fragile for manual handling in most cases and is typically wound by machine as enameled magnet wire.