PURPOSE: To match the position of the threaded holes in the main body to the position of the pan head bolt holes of a part to be fastened with reference to the threaded holes already bored in the part that is to be fastened by pan head bolts.

CONSTITUTION: In replacing the liner 2, the play holes D1 only are drilled into it. The liner 2 in this condition is mounted provisionally on the main body 1. The tapered portions of the holes in the liner 2 are machined by the pan head drill 5 whcih matches the tap drill hole D2 of the main body 1 and has the bushing 6 and core. In this drilling the center of the drill 5 coincides with the center of the threaded hole of the main body 1 through the bushing 6, and the center of the tapered portions in the liner 2 is also machined concentrically. Incidentally the bushing 6 protects the threaded hole of the main body 1.