International brands have already registered more than 1,000 aluminum, each grade there are a variety of state, the hardness, strength, corrosion resistance, workability, welding, decorative, etc. There are obvious differences. Select grade aluminum and state, is difficult to satisfy both the above aspects, it is not necessary, should be based on product performance requirements, the use of the environment, process and other factors, the priorities set various properties before they make a reasonable selection, performance guarantees under the reasonable control of the former is the cost. 
 Hardness: many customers are very concerned about when buying aluminum, hardness, chemical composition of alloys of choice with a direct relationship. Second, the various states have a greater impact, from the highest possible hardness of view, the 7 Series, 2 lines, 4 lines, 6 Series, 5 Series, 3 Series, 1 Series, by turns. 
 Hardness: product design strength is an important factor must be considered, as it is the aluminum alloy component as the component should be based on the pressure, select the appropriate alloy. Minimum strength aluminum, and 2 and 7 Series, Department of the highest heat-type alloy, hardness and strength of relationship between a certain lower phase. 
 Corrosion resistance: corrosion resistance, including chemical corrosion, stress corrosion and other properties. In general, a system the best corrosion resistance of aluminum, 5 and performed well, followed by the 3 Series and 6 Series, 7 series 2 system and poor. Corrosion resistance of the principle of selection should be based on the use of the occasion. High-strength alloy corrosion environments, you must use a variety of composite materials for corrosion protection. 
 Processing of: processing performance package insert forming properties and cutting performance. Because with the state of formability, the choice of alloy grades, the need to consider the scope of the strength of the various states, usually forming high strength materials is not easy. If Taiwan were to be on the aluminum bending, stretching, deep drawing and other forming process, complete the forming of the annealed condition the best materials, on the contrary, the material forming heat treatment of the worst. Poor cutting aluminum alloy, for molds, machinery parts and other necessary cutting of better contrast, low intensity were poor machinability of the mold, cutting machine parts and other needed products, the cutting of aluminum is important considerations. 
 Welding: aluminum welding majority had no problems, especially some 5 series aluminum alloy, is designed for welding into account, the opposite sides of the statement, Part 2 and 7 Series aluminum welding more difficult. 
 Decorative properties: aluminum used in decoration, and certain other occasions, it needs to surface anodizing, painting and other processing, to obtain the corresponding color and surface structure, then the focus should be considered decorative, general and words, the better corrosion resistance material, anodizing, surface processing performance, painting and performance are excellent. 
 Other features: In addition to the above characteristics, there are electrical conductivity, wear resistance, heat resistance and so on. In the selection can also be taken into account. 
 Grade: 
 Aluminum: 1A99 1A97 1A95 1A93 1A90 1A85 1A80 1A80A 1070 1070A 1370 A1060 1050 1050A 1A50 1350 1145 1350 1A30 1160 1200 1235 
 2 Series: 2A01 2A02 2A04 2A06 2A10 2A11 2B11 2A12 2A13 2A14 2A16 2B16 2A17 2A20 2A21 2A25 2A49 2A50 2A70 2A80 2A90 2004 2011 2014 2014 A 2214 2017 2017A 2177 2218 2618 2219 2024 2124 
 3 Series: 3A21 3003 3103 3004 3005 3105 
 4 Series: 4A03 4A11 4A13 4A17 4004 4032 4043 4043 A 4047 4047A 
 5 Series: 5A01 5A02 5A03 5A05 5A06 5B06 5A12 5A30 5A33 5A41 5A42 5A66 5005 5019 5050 5251 5052 5154 5154A 5454 5154A 5754 5056 5356 5456 5082 5182 5086 
 6 series: 6A02 6B02 6A51 6101 6101A 6005 6005A 6351 6060 6061 6063 6063A 6070 6181 6082 
 7 Series: 7A01 7A03 7A04 7A05 7A09 7A10 7A15 7A19 7A31 7A33 7A52 7003 7005 7020 7022 7050 7075 7475 8A06 8011 8090