CNP (C-channel / lip channel) is formed from steel coil and used for roof purlins and light wall framing. When estimating materials, the figure you need is almost always the same: what does CNP weigh per metre and per length?
How to read CNP sizes
CNP size is written as height × flange width × lip × thickness, e.g. 100 × 50 × 20 × 2.3 mm. For the same size, a thicker section means more weight — always check the kg/m column.
CNP weight formula
CNP is bent from coil plate, so its weight can be calculated from the developed width of the plate:
Weight (kg/m) = developed width (mm) × thickness (mm) × 0.00785
Developed width ≈ height + (2 × flange width) + (2 × lip)
CNP weight table (popular sizes)
| Size (mm) | Weight (kg/m) | Weight / 6 m (kg) |
|---|---|---|
| 60 × 30 × 10 × 1.6 | 1.76 | 10.5 |
| 75 × 45 × 15 × 1.6 | 2.45 | 14.7 |
| 75 × 45 × 15 × 2.0 | 3.06 | 18.4 |
| 100 × 50 × 20 × 1.6 | 3.01 | 18.1 |
| 100 × 50 × 20 × 2.0 | 3.77 | 22.6 |
| 100 × 50 × 20 × 2.3 | 4.33 | 26.0 |
| 125 × 50 × 20 × 2.3 | 4.78 | 28.7 |
| 125 × 50 × 20 × 3.2 | 6.66 | 39.9 |
| 150 × 50 × 20 × 2.3 | 5.24 | 31.4 |
| 150 × 50 × 20 × 3.2 | 7.28 | 43.7 |
| 150 × 65 × 20 × 3.2 | 8.04 | 48.2 |
| 200 × 75 × 20 × 3.2 | 9.80 | 58.8 |
The weights above are theoretical values at a steel density of 7.85 g/cm³. Under-nominal (“banci”) thickness lowers the weight and the purlin’s load capacity — see the CNP channel page.
Tips for estimating
- Total the purlin/frame length, then multiply by kg/m.
- Use the 6 m standard length to work out bar count.
- Check the actual thickness — always compare price per kg, not per length.
Need a CNP price today?
Marselus Steel keeps CNP in ready stock at our Tipar Cakung warehouse, North Jakarta. See what drives the CNP price or contact our team on WhatsApp for the latest quote.
