This series has 40 standard constructions with a copper cross-section from 0.5 to 20.1 mm². A 0.2 mm strand is optimal up to 25 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 0.15 mm strand; for lower frequencies, 0.25 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 |
|---|---|---|---|---|---|
| 16×0.2 | 16 | 0.5 | 1.254 | 5.671 | 34.66 |
| 32×0.2 | 32 | 1 | 1.774 | 9.552 | 17.33 |
| 48×0.2 | 48 | 1.5 | 2.173 | 14.328 | 11.55 |
| 64×0.2 | 64 | 2 | 2.509 | 19.104 | 8.66 |
| 80×0.2 | 80 | 2.5 | 2.805 | 23.88 | 6.93 |
| 95×0.2 | 95 | 3 | 3.057 | 28.357 | 5.84 |
| 110×0.2 | 110 | 3.5 | 3.289 | 32.835 | 5.04 |
| 128×0.2 | 128 | 4 | 3.548 | 38.208 | 4.33 |
| 144×0.2 | 144 | 4.5 | 3.763 | 42.984 | 3.85 |
| 160×0.2 | 160 | 5 | 3.967 | 47.76 | 3.47 |
| 175×0.2 | 175 | 5.5 | 4.149 | 52.237 | 3.17 |
| 192×0.2 | 192 | 6 | 4.345 | 57.312 | 2.89 |
| 207×0.2 | 207 | 6.5 | 4.512 | 61.789 | 2.68 |
| 224×0.2 | 224 | 7 | 4.694 | 66.864 | 2.48 |
| 240×0.2 | 240 | 7.54 | 4.858 | 73.132 | 2.31 |
| 255×0.2 | 255 | 8 | 5.008 | 76.117 | 2.17 |
| 270×0.2 | 270 | 8.5 | 5.153 | 80.595 | 2.05 |
| 288×0.2 | 288 | 9 | 5.322 | 85.968 | 1.93 |
| 300×0.2 | 300 | 9.4 | 5.432 | 89.55 | 1.85 |
| 320×0.2 | 320 | 10 | 5.61 | 95.52 | 1.73 |
| 335×0.2 | 335 | 10.5 | 5.74 | 99.998 | 1.66 |
| 350×0.2 | 350 | 11 | 5.867 | 104.475 | 1.58 |
| 365×0.2 | 365 | 11.5 | 5.991 | 108.953 | 1.52 |
| 384×0.2 | 384 | 12 | 6.145 | 114.624 | 1.44 |
| 400×0.2 | 400 | 12.6 | 6.272 | 119.4 | 1.39 |
| 415×0.2 | 415 | 13.07 | 6.396 | 124.165 | 1.392 |
| 430×0.2 | 430 | 13.5 | 6.503 | 128.355 | 1.29 |
| 445×0.2 | 445 | 14 | 6.615 | 132.832 | 1.301 |
| 460×0.2 | 460 | 14.5 | 6.726 | 137.31 | 1.21 |
| 475×0.2 | 475 | 14.9 | 6.835 | 141.787 | 1.17 |
| 495×0.2 | 495 | 15.55 | 6.977 | 147.725 | 1.12 |
| 510×0.2 | 510 | 16 | 7.082 | 152.235 | 1.09 |
| 525×0.2 | 525 | 16.5 | 7.185 | 156.713 | 1.06 |
| 540×0.2 | 540 | 17 | 7.287 | 161.19 | 1.03 |
| 560×0.2 | 560 | 17.6 | 7.421 | 167.16 | 0.99 |
| 575×0.2 | 575 | 18.1 | 7.52 | 171.637 | 0.96 |
| 590×0.2 | 590 | 18.5 | 7.617 | 176.115 | 0.94 |
| 605×0.2 | 605 | 19 | 7.714 | 180.593 | 0.92 |
| 620×0.2 | 620 | 19.5 | 7.809 | 185.07 | 0.89 |
| 640×0.2 | 640 | 20.1 | 7.934 | 191.04 | 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 — 0.2 mm, up to 25 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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