Made of High Quality Tool Steel , this is a high quality tailstock die holder for threading, tapping and reaming operation on your lathe machine Imperial dies size holding capacity - 13/16", 1" & 1-1/2" Inches Tap holding capacity of the 2 tap wrenches supplied along are : 1/16" to 1/4" (M2 to M6) & 1/4" to 1/2" (M6 to M12) Inches Comes with a hard and precisely ground shank. The Die for threading purpose is hold in the various Die holder sizes. The internal bore threading/ tapping is done by mounting the tap wrench head as per tap size between the above advised range is moved toward the rotating job in the lathe's chuck.