Answer box
Aluminium extrusions under CN 7604 cover bars, rods and profiles made by pushing heated aluminium billet through a die. The extrusion process itself uses electricity (not counted for CBAM aluminium direct scope), natural gas for billet pre-heat, and some process energy. The single biggest data point is the origin and embedded emissions of the unwrought aluminium (CN 7601) your supplier melts to make the billet.
Production route
- Billet casting from unwrought aluminium (CN 7601), often blended with scrap.
- Homogenisation heat treatment (gas-fired).
- Pre-heat before extrusion.
- Extrusion through the die (electrical press).
- Age hardening heat treatment.
- Cut-to-length, surface treatment (anodising, powder coating).
Where primary vs recycled matters
Extrusion billet is often made by blending primary aluminium (fresh from smelter) with secondary aluminium (clean scrap, often extrusion offcuts from the same plant). The engine prompts for the split so the mass balance is right.
What to ask your supplier
- Natural gas bills for billet pre-heat and homogenisation.
- Unwrought aluminium procurement: smelter name, country, primary vs recycled share, PFC data.
- Scrap input: percentage of total metal input, cleanliness class.
- Production tonnes by profile family / CN subheading.
- Surface treatment energy if done in-house.