A horizontal gear hobbing machine is a special type of gear hobbing machine in which the tool is located horizontally above the workpiece. In contrast, a vertical gear hobbing machine has the tool vertical to the machining surface. Horizontal gear milling machines typically offer greater stability when machining parts and better accessibility to the workholding surface. Also, larger parts can be machined on a horizontal machine because it has a larger work surface. Horizontal gear hobbing machines are often used in the production of large gears, gear parts, bearing housings and other components.