Aluminium alloy series and temper designation
Wrought aluminium alloys follow a four-digit system: 1xxx pure aluminium (foil, conductors), 3xxx manganese (cans, roofing), 5xxx magnesium and seawater-resistant (ships, tanks), 6xxx magnesium-silicon (extrusions, 6063/6061), 7xxx zinc and high strength (aerospace, 7075). The temper code after a dash gives the condition: O annealed, H strain-hardened (H14, H24), T heat-treated (T5 artificially aged, T6 solution-treated and artificially aged). Primary ingot is priced at LME plus a regional premium, and semi-finished products add a conversion premium on top.
Related terms
London Metal Exchange (LME) and commodity exchanges
The exchange that sets global reference prices for non-ferrous metals such as copper, aluminium, zinc, nickel, lead, tin and cobalt; its official prices and monthly averages are used as indices in physical contracts. A physical buyer pays the LME price plus a premium that depends on origin, brand and delivery location (e.g. the Rotterdam aluminium premium). Other key exchanges: CME/COMEX (copper, gold), ICE (Brent, cocoa, coffee, sugar, cotton), CBOT (soybeans, corn, wheat), SHFE (Shanghai metals), DCE and ZCE (Chinese plastics, iron ore and agricultural futures) and Bursa Malaysia (palm oil).
Steel grade designation (EN, ASTM, AISI, JIS, GB)
Steels carry different names in different standard systems. In the European system (EN 10027) a letter shows the use and a number the minimum yield strength: S235JR is a structural steel with 235 MPa and impact tested at 20 °C, while S355J2 is tested at –20 °C. Approximate equivalents are ASTM A36 or A572 Gr.50, JIS SS400 in Japan and GB Q235/Q355 in China; for stainless, AISI 304 ≈ EN 1.4301. Equivalents are not identical, so chemistry and mechanical values should be checked on the certificate.