How is the CBAM figure for screws and nuts made from bought steel rod calculated?
The Commission's iron and steel guidance works it through: carbon steel rod at 1.567 t CO2 per tonne, times 1.176 t of rod per tonne of product, gives 1.843; natural gas adds 0.196, for 2.039 t CO2 per tonne of screws and nuts. Electricity need not be reported.
The plant in the example
- Buys carbon steel and stainless rod, hot rolls it to wire, then cuts and forges screws and cuts, forges and machines nuts.
- Burns 3.5 GJ of natural gas per tonne of product. Electricity is used but not monitored in the definitive period.
- Two production processes, because the CN codes differ: carbon steel (7318 12 90, 7318 14 91, 7318 14 99, 7318 15 58, 7318 15 68) and stainless (7318 12 10, 7318 14 10, 7318 15 52, 7318 15 62).
Why more rod than product
Cutting and machining make scrap, and scrap carries zero embedded emissions. So every tonne of rod's emissions lands in the good parts: 20,000 t of carbon steel rod made 17,000 t of product and 3,000 t of scrap, a ratio of 1.176. Stainless: 10,000 t made 8,200 t, a ratio of 1.220.
Doing it with your numbers
- Total rod used and product made in the year, per production process.
- Divide rod by product for the ratio.
- Multiply by the rod's figure: your supplier's verified value or the EU default value.
- Add your own fuel: GJ per tonne x 56.1 t CO2 per TJ for natural gas, divided by 1,000.
- Report one figure per production process, with the alloy and scrap figures your buyer must declare.
Free allocation in the same example
The guidance gives 1.499 t CO2 per tonne for the carbon steel screws: 1.242 for the rod, times 1.176, plus the process benchmark of 0.038. Stainless: 0.919 x 1.220 + 0.038 = 1.159.
Worked example from the Commission's guidance
- Carbon steel rod: 1.567 t CO2 per tonne
- Rod per tonne of product: 20,000 / 17,000 = 1.176
- Rod's share: 1.567 x 1.176 = 1.843
- Natural gas: 3.5 GJ x 56.1 t CO2 per TJ = 0.196
- Carbon steel screws and nuts: 1.843 + 0.196 = 2.039 t CO2 per tonne
- Stainless route: 1.783 x 1.220 = 2.175, plus 0.196 = 2.371 t CO2 per tonne
These are the Commission's example values, not Indian figures. Use your rod supplier's verified figure, or the default value, and your own gas readings.
What Senseible does here
Senseible's CBAM Suite builds this figure from your rod purchase invoices, gas bills and production records. We build it from your records, check every figure in-house, and an accredited verifier we partner with signs it off. Have your own verifier? Send it to them.
Last reviewed 2026-11-01.