This series has 40 standard constructions with a copper cross-section from 0.5 to 20 mm². A 0.1 mm strand is optimal up to 100 kHz — at these frequencies the litz wire delivers the highest winding Q factor by minimizing the skin and proximity effects. For higher-frequency tasks you move to a 0.071 mm strand; for lower frequencies, 0.15 mm. All constructions are manufactured by DIADA LLC (Diada-Electro) to TU 27.32.11-019-59596873-2025 and are available in 50+ insulation grades — from PTFE and polyimide to rectangular forming.
| Designation | Strands | Cross-section, mm² | Ø, mm | Mass, kg/km | R, Ω/km |
|---|---|---|---|---|---|
| 63×0.1 | 63 | 0.5 | 1.311 | 4.75 | 35.21 |
| 128×0.1 | 128 | 1 | 1.868 | 9.907 | 17.33 |
| 190×0.1 | 190 | 1.5 | 2.276 | 11.61 | 11.67 |
| 255×0.1 | 255 | 2 | 2.637 | 19.737 | 8.7 |
| 315×0.1 | 315 | 2.5 | 2.931 | 24.381 | 7.04 |
| 372×0.1 | 372 | 3 | 3.185 | 28.793 | 5.96 |
| 440×0.1 | 440 | 3.5 | 3.464 | 34.056 | 5.04 |
| 500×0.1 | 500 | 4 | 3.692 | 38.7 | 4.44 |
| 570×0.1 | 570 | 4.5 | 3.942 | 44.118 | 3.89 |
| 630×0.1 | 630 | 5 | 4.144 | 48.762 | 3.52 |
| 700×0.1 | 700 | 5.5 | 4.369 | 54.18 | 3.17 |
| 750×0.1 | 750 | 5.9 | 4.522 | 58.05 | 2.96 |
| 828×0.1 | 828 | 6.5 | 4.751 | 64.087 | 2.68 |
| 891×0.1 | 891 | 7 | 4.929 | 68.963 | 2.49 |
| 950×0.1 | 950 | 7.5 | 5.089 | 73.53 | 2.33 |
| 1020×0.1 | 1020 | 8 | 5.274 | 81.27 | 2.17 |
| 1080×0.1 | 1080 | 8.5 | 5.426 | 83.592 | 2.05 |
| 1140×0.1 | 1140 | 9 | 5.575 | 88.236 | 1.95 |
| 1215×0.1 | 1215 | 9.5 | 5.756 | 94.041 | 1.83 |
| 1275×0.1 | 1275 | 10 | 5.896 | 98.685 | 1.74 |
| 1350×0.1 | 1350 | 10.6 | 6.067 | 104.49 | 1.64 |
| 1400×0.1 | 1400 | 11 | 6.178 | 108.36 | 1.58 |
| 1458×0.1 | 1458 | 11.5 | 6.305 | 112.849 | 1.52 |
| 1520×0.1 | 1520 | 12 | 6.438 | 117.648 | 1.46 |
| 1600×0.1 | 1600 | 12.6 | 6.605 | 123.84 | 1.39 |
| 1650×0.1 | 1650 | 13 | 6.707 | 127.71 | 1.34 |
| 1725×0.1 | 1725 | 13.5 | 6.858 | 133.515 | 1.29 |
| 1792×0.1 | 1792 | 14 | 6.99 | 138.701 | 1.24 |
| 1856×0.1 | 1856 | 14.6 | 7.114 | 143.654 | 1.2 |
| 1900×0.1 | 1900 | 15 | 7.197 | 147.06 | 1.17 |
| 1980×0.1 | 1980 | 15.5 | 7.347 | 153.252 | 1.12 |
| 2040×0.1 | 2040 | 16 | 7.458 | 157.896 | 1.09 |
| 2100×0.1 | 2100 | 16.5 | 7.567 | 162.54 | 1.06 |
| 2160×0.1 | 2160 | 17 | 7.674 | 167.184 | 1.03 |
| 2240×0.1 | 2240 | 17.5 | 7.815 | 173.376 | 0.99 |
| 2295×0.1 | 2295 | 18 | 7.91 | 177.633 | 0.97 |
| 2368×0.1 | 2368 | 18.5 | 8.035 | 183.283 | 0.94 |
| 2432×0.1 | 2432 | 19 | 8.143 | 188.237 | 0.91 |
| 2484×0.1 | 2484 | 19.5 | 8.23 | 185.25 | 0.89 |
| 2560×0.1 | 2560 | 20 | 8.354 | 198.144 | 0.87 |
Three parameters drive the choice: frequency (sets the strand diameter), current (sets the copper cross-section), and temperature and environment (set the insulation grade). We work backwards: frequency first — it unambiguously narrows the series.
The copper skin depth falls as frequency rises. Once it becomes comparable to the strand radius, a thicker strand stops helping — you need a thinner one.
| Frequency | Strand diameter |
|---|---|
| up to 15 kHz | 0.25 mm |
| up to 25 kHz | 0.2 mm |
| up to 50 kHz | 0.15 mm |
| up to 100 kHz | 0.1 mm |
| up to 200 kHz | 0.071 mm |
| above 200 kHz | 0.05 mm (made to order) |
This series — 0.1 mm, up to 100 kHz.
For transformer and inductor windings, a typical current density is 3–5 A/mm² (depending on the cooling regime and the allowable temperature rise).
| Operating current | Cross-section |
|---|---|
| 2–3 A | 0.5 mm² |
| 4–6 A | 1 mm² |
| 7–10 A | 2 mm² |
| 15–20 A | 4 mm² |
| 30–40 A | 8 mm² |
| 60–80 A | 16 mm² |
For an accurate calculation, account for the waveform (sine / PWM / pulse) — it sets the RMS value and the losses.
Once the cross-section is set, you choose the grade — it determines the operating temperature, chemical resistance, breakdown voltage and cross-section shape.
Not sure — use the winding calculator: it picks the nearest standard construction for your turns count, inductance and current. Or read the article on skin effect and proximity effect — with formulas and examples.
The frequency-range boundaries are calculated by the Sullivan criterion d ≤ δ/2 (copper skin depth δ = 2.09/√f[kHz] mm). Source: Sullivan C.R., Zhang R.Y. "Simplified Design Method for Litz Wire" — IEEE APEC 2014.
Popular versions — the full catalog is on the "Products" page (50+ grades).
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