1. Oxidizability. When selecting, you can swipe on the surface of the profile to see if the oxide film on its surface can be wiped off.

2. Color. The same aluminum alloy profile color should be consistent, such as color difference is obvious, that is, not suitable for purchase. Generally normal aluminum alloy profile cross-section color is silver-white, uniform texture, if the color is dark, can be concluded to recycle aluminum or waste aluminum furnace forged.

3. Flatness. Check the surface of the aluminum alloy profile and there should be no dents or bulging. Formal manufacturers processed out of aluminum profiles, flat surface, bright, if it is a small workshop due to machines or raw materials, profile surface will appear slightly bumpy, such aluminum alloy profile synthetic balcony window later easily oxidized and deformed.

4. Intensity. When purchasing, use the hand to bend the profile moderately, if you can  bend the profile without effort, then you can determine that the strength of the aluminum profile is not up to standard. And the strength of the profile is not as hard as possible, aluminum has a certain toughness, non-hard material, the use of this characteristic is good forging to create different shapes, so the owner in the purchase need to identify the brand, carefully observe.

5. Thickness. Commonly used 70, 90 series of aluminum window profiles, its wall thickness should be 1.2-2.0 mm.

6. Brightness. Aluminum alloy doors and windows to avoid the purchase of surfaces with open air bubbles and ash slag, as well as cracks, burrs, peeling and other obvious defects of the profile. If there are the above phenomena, it can be concluded that the recovery of aluminum or waste aluminum secondary processing molding, such materials due to unearrayed texture, alloy ratio clutter, when the later easy to crack oxidation.oy ratio clutter, when the later easy to crack oxidation.