1、Heat treated 45# steel taps and alloy steel dies are are of good hardness, strong strength and long durability 2、All taps and dies are clearly marked with size for easy and fast finding 3、The tap wrench is adjustable to fit different taps and can hold tap firmly and securely 4、This set also includes screw pitch gauge that you can use to check created thread 5、This tap and die set is perfect for use on vehicles and machinery to create threads