1. Aluminum alloy thickness: aluminum alloy sliding doors have 70 series and 90 series of these two, aluminum alloy interior aluminum interior sliding doors generally use 70 series on it. The number of series is actually the number of millimeters that represent the thickness of the door frame. Aluminum alloy sliding window has 55 series, 60 series, 70 series, 90 series four kinds. The selection of the series is based on the size of the window hole and the local wind pressure to set. Aluminum windows used to close the balcony should not be less than 70 series.
2. Aluminum alloy strength: Tensile strength should be achieved per square millimeter mm 157 Newton, yield strength to reach 108 Newton per square millimeter. In the purchase time, you can hand to bend the profile, let go after it can not return to its original state.
3. Aluminum alloy color: the same aluminum alloy color should be consistent, if it is obvious color, then do not buy.
4. Aluminum alloy profile: check the surface of aluminum alloy profiles, aluminum profiles should be no depression or bulging.
5. Glossiness of aluminum alloy profiles: aluminum alloy profiles to avoid the opening of the surface of the bubble and ash and there are cracks, burrs or skin and other obvious defects in the profile.
6. Aluminum alloy oxide degree: the thickness of the oxide film should reach 10 microns. When you buy the surface of the surface can be a little light to see it on the surface of the oxide film is not you can erase.