Carbon Steel—Carbon steel taps are for thread repair and occasional tapping.

High-Speed Steel—High-speed steel taps and dies last longer than carbon steel when used on similar material.

Plug Chamfer—Plug-chamfer taps are a versatile choice for most tapping applications. With 3-5 chamfered cutting threads, they require moderate torque and are often used for start-to-finish tapping of through holes and closed-end holes. However, they do not start threads as easily as taper-chamfer taps. When using them to tap closed-end holes, be sure to leave sufficient space at the bottom for chips to accumulate.

Taper Chamfer—Taper-chamfer taps have 7-10 chamfered threads at the tip for cutting into the workpiece. They require less torque than other chamfer types, making them a good choice for starting threads and tapping through holes. However, a longer taper means that they cannot thread as close to the bottom of closed-end holes.

Hex—Hex-shaped dies are for thread repair and can be used with conventional wrenches.