uploaded by Chris Dodds - Thorne & Derrick Sales & Marketing Manager
Class 1 & 2: Shows the obligatory number of strands
Class 5 & 6: Shows the maximum strand diameter, may be fewer strands as long as the maximum ohms/km is not exceeded
Ohms Ω/km: Shows the maximum resistance in that is permissible for untinned copper conductors in the stranding classes indicated
| Area sqmm | Stranding Class 1 |
Stranding Class 2 |
Ohms Ω/km |
Stranding Class 5 |
Stranding Class 6 |
Ohms Ω/km |
| 0.14 | 18 x 0.10 | 18 x 0.10 | 138.0 | |||
| 0.25 | 14 x 0.16 | 32 x 0.10 | 79.0 | |||
| 0.34 | 19 x 0.16 | 42 x 0.10 | 57.0 | |||
| 0.5 | 1 x 0.80 | 7 x 0.30 | 36.0 | 16 x 0.21 | 28 x 0.10 | 39.0 |
| 0.75 | 1 x 0.97 | 7 x 0.37 |
24.5 | 24 x 0.21 | 42 x 0.16 | 26.0 |
| 1.0 | 1 x 1.13 | 7 x 0.43 | 18.1 | 32 x 0.21 | 56 x 0.16 | 19.5 |
| 1.5 | 1 x 1.38 | 7 x 0.53 | 12.1 | 30 x 0.26 | 84 x 0.16 | 13.3 |
| 2.5 | 1 x 1.78 | 7 x 0.67 | 7.41 | 50 x 0.26 | 140 x 0.16 | 7.98 |
| 4.0 | 1 x 2.26 | 7 x 0.85 | 4.61 | 56 x 0.31 | 224 x 0.16 | 4.95 |
| 6.0 | 1 x 2.76 | 7 x 1.04 | 3.08 | 84 x 0.31 | 192 x 0.21 | 3.30 |
| 10.0 | 1 x 3.57 | 7 x 1.35 | 1.83 | 80 x 0.41 | 320 x 0.21 | 1.91 |
| 16.0 | 1 x 4.51 | 7 x 1.70 | 1.15 | 128 x 0.41 | 512 x 0.21 | 1.21 |
| 25.0 | 7 x 2.14 | 0.72 | 200 x 0.41 | 800 x 0.21 | 0.78 | |
| 35.0 | 7 x 2.52 | 0.524 | 280 x 0.41 | 1120 x 0.21 | 0.554 | |
| 50.0 | 19 x 1.78 | 0.387 | 400 x 0.41 | 705 x 0.31 | 0.386 | |
| 70.0 | 19 x 2.14 | 0.268 | 356 x 0.51 | 990 x 0.31 | 0.272 | |
| 95.0 | 19 x 2.52 | 0.193 | 485 x 0.51 | 1340 x 0.31 | 0.206 | |
| 120 | 37 x 2.03 | 0.153 | 614 x 0.51 | 1690 x 0.31 | 0.161 | |
| 150 | 37 x 2.25 | 0.124 | 765 x 0.51 | 2123 x 0.31 | 0.129 | |
| 185 | 37 x 2.52 | 0.099 | 944 x 0.51 | 1470 x 0.41 | 0.106 | |
| 240 | 61 x 2.25 | 0.074 | 1225 x 0.5 | 1905 x 0.41 | 0.081 | |
| 300 | 61 x 2.52 | 0.060 | ||||
| 400 | 61 x 2.85 | 0.046 | ||||
| 500 | 61 x 3.20 | 0.036 |
Thorne & Derrick International are specialist distributors of LV, MV & HV Cable Installation, Jointing, Duct Sealing, Substation & Electrical Equipment – servicing UK and global businesses involved in cable installations, cable jointing, substation, overhead line and electrical construction at LV, 11kV, 33kV and EHV.
THORNE & DERRICK Product Categories: Duct Seals | Cable Cleats | Cable Glands | Electrical Safety | Arc Flash Protection | Cable Jointing Tools | Cable Pulling | Earthing | Feeder Pillars | Cable Joints LV | Joints & Terminations MV HV
Published 09 Jan 2026
We’d like to welcome our newest addition to the Thorne and Derrick team! Eva will be joining us as a content creator apprentice at our office in Chester-Le-Street. Eva will bring fresh new ideas to all of our social...
Published 09 Jan 2026
Insulating Matting Recommendations and Guidance for Electrical Safety Guest Blog From COBA Electrical safety is non-negotiable, especially when working around live switchgear, high-voltage panels, and electrical distribution equipment. One critical but sometimes overlooked safeguard is electrical insulating matting, designed...
