According to the national standard, "aluminum ingots for remelting are divided into six grades according to chemical composition, namely, al99.85, Al99.80, Al99.70, Al99.60, Al99.50 and Al99.00" (note: the number after Al is aluminum content). What some people call "A00" aluminum is actually aluminum with a purity of 99.7%, which is called "standard aluminum" in the London market. As we all know, China's technical standards in the 1950s all came from the former Soviet Union. "A00" is a Russian brand in Soviet national standards, and "A" is a Russian letter, not an English "A" or a Chinese phonetic alphabet. In line with international standards, it is more accurate to call it "standard aluminum". Standard aluminum is an aluminum ingot containing 99.7% aluminum.