There are mainly the following steps:
There are 70 series and 90 series aluminum alloy sliding doors, and the 70 series of aluminum sliding doors in the house can be used. The number of series indicates the number of millimeters of the thickness of the door frame. Aluminum alloy sliding windows are available in 55 series, 60 series, 70 series and 90 series. The selection of the series should be based on the size of the window and the local wind pressure. The aluminum alloy sliding window used as a closed balcony should be no less than the 70 series.
The tensile strength should be 157 Newtons per square meter and the yield strength should be 108 Newtons per square millimeter. When purchasing, you can use your hand to bend the profile moderately, and you should be able to recover after loosening your hand.
The color of the same aluminum alloy profile should be the same, if the color difference is obvious, it is not suitable for purchase.
Check the surface of the aluminum alloy profile without dents or bulging.
Aluminum alloy doors and windows avoid the appearance of open air bubbles (white spots) and ash (black spots), as well as cracks, burrs, peeling and other obvious defects.
6. Oxidation degree
The oxide film should be 10 microns thick. When you purchase, you can scratch the surface of the profile to see if the oxide film on the surface can be wiped off.