Use a single kit for many sizes of internal and external threads. The taps and dies are for use on most metal and plastic.

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.