When installing stainless steel internal expansion screws, the screws will expand as the nuts or bolts are tightened, and they will be tightly embedded in the material hole to form a strong connection. The expansion action occurs inside the thread, which increases the friction with the hole wall. It is suitable for a variety of occasions that require high-strength fixing, especially in environments with large loads and corrosion resistance. It is widely used in construction, machinery, electrical, outdoor facilities and other fields, with simple installation methods and long-lasting durability. It is widely used in fixing system windows in China.