A window friction hinge is a type of hinge commonly used in modern windows to provide smooth and controlled opening and closing. It is a device that allows the window sash to pivot around an axis to open and close, and also provides a certain amount of resistance to prevent the window from slamming shut. The friction hinge is adjustable, allowing the user to control the amount of force required to move the window. It is a popular choice for both residential and commercial windows due to its smooth operation and ease of use. Friction hinges come in different sizes and designs to suit different types and sizes of windows.