This tool holder can be used with either a narrow or wide tool for roughing or finishing cuts. It is most commonly used for straight shoulder work where a clearance angle has been ground on the tool. The Forming Dovetial Double Deck is generally popular because it adapts to several positions on the machine, producing a variety of work. Dovetail tool blanks sized for individual tool holders are also available. Rigidity is key to screw machine and automatic rough forming. Slater Tools gives you this and adds a double deck position.