CHARLES CHRISTOPHER HUFF
Pilots at Meadowridge Ln, Midland, TX

4478298, Oct 23, 1984

Dec 13, 1982

6/449137

Lewis W. Hake - Midland TX
Charles F. Huff - Midland TX
J. Wayne Miller - Midland TX

Petroleum Concepts, Inc. - Midland TX

E21B 1046

175329

A polycrystalline diamond compact is a polycrystalline diamond wafer attached to a tungsten carbide substrate forming a disc. In this form, it is attached to a stud which is attached within a drill bit. The compact is attached to the stud with the aid of a positioning ring. When the stud is made of impact resistant material, a full pedestal may be formed on the stud to facilitate the use of the positioning ring. When the stud is made of brittle material, the positioning ring is attached to the flat face of the stud without a pedestal. The ring is positioned on a stud and the disc inserted in the ring so that the disc is positioned against the bonding surface. The disc remains in position against the bonding surface during the handling before and during the bonding process. As a second embodiment, the polycrystalline diamond compact is smaller than the disc itself and the remainder of the disc is formed of metal having the same thickness as the polycrystalline diamond compact or its tungsten carbide substrate. The shape of the smaller polycrystalline diamond compact may be semi-circular, circular, polygon shaped, (i. e.