Prime-line 3/4 in x 5/16 in 0.020 roll formed screen frame is designed for use on sliding aluminum windows. also often used to make replacement storm door screens. Prime-line screen frames are manufactured with a slight camber (bow) that provides tension to the finished screen. This features helps eliminate wrinkles in the screen fabric. The screen frame accepts up to 0.185 vinyl spline and uses miter (angle) cut screen corners.