First, examine the materials. High-quality aluminum alloy doors and windows use aluminum profiles whose thickness, strength, and oxide film meet relevant national standards. The main load-bearing members of aluminum alloy windows should have a wall thickness of at least 1.4 mm, and those of aluminum alloy doors should have a wall thickness of at least 2.0 mm. The tensile strength should reach 157 Newtons per square millimeter, the yield strength should reach 108 Newtons per square millimeter, and the oxide film thickness should reach 10 micrometers. If these standards are not met, the aluminum alloy doors and windows are of inferior quality and should not be used.
Second, examine the workmanship. High-quality aluminum alloy doors and windows are finely crafted, meticulously installed, have good sealing performance, and open and close smoothly. Inferior aluminum alloy doors and windows are made with indiscriminately selected aluminum profile series and specifications, are crudely made, use sawing instead of milling, are not installed according to requirements, have poor sealing performance, and are difficult to open and close. They not only leak air and water and may experience glass breakage, but also are prone to having sliding parts or glass blown off or knocked off by strong winds or external forces, causing damage and injury.
Third, consider the price. Generally, high-quality aluminum alloy doors and windows are about 30% more expensive than inferior ones due to higher production costs. Some aluminum alloy doors and windows made with aluminum profiles only 0.6-0.8 mm thick have tensile and yield strengths far below national standards, making them very unsafe. Furthermore, many small-scale aluminum alloy door and window manufacturers lack understanding of their structural characteristics and performance. To reduce costs, they cut corners and use inferior materials, resulting in products with significant safety risks; these should generally be avoided. It is best to choose products from reputable aluminum alloy door and window manufacturers.
