An angle plate is a metal plate with 90-degree angles used as a clamping or holding device in metalworking and woodworking applications. It typically has two perpendicular sides and one or more holes for attaching it to a work surface or other clamping device. Angle plates can be used to hold workpieces at a 90-degree angle for drilling, milling, or other machining operations. They are also useful for setting up workpieces at a specific angle for welding.