This threaded drill steel is used for all types of hand drilling in conjunction with a specific set of drill bits. It is designed with the shoulder drive connection for easy extraction from the drilled hole. The mating shoulder of the drill steel and the drill bit carry the brunt of the torque, relieving the stress on the threads

Shank Size: 7/8 x 4 1/4
Thread Type: H-Thread Hollow Drill Steel
Length: 24"