cross section with a base 10 and upstanding legs 11 and 12 each leg is formed with a center apex which corresponds with the center apex 8 of cutting element 4 when the cutting element is supported in the bridge the upwardly extending legs 11 and 12 slightly embrace opposite faces of the cutting element supported in bridge 3 to impart strength to the cutting element and prevent shear by horizontal forces during drilling as shown in fig5 and 7 each leg of bridge 3 has a right angle cutout 15 which is equal to approximately one half of the length of the bridge each cutout 15 is located on the portion of the bridge leg next to that portion of a face of cutting element 4 which has its upper edge exposed to form a cutting edge 7 the lower edge 16 of each cutout 15 is formed with a downwardly directed chamfer 17 which assists in the removal of debris during cutting and prevents separation of a face of cutting element 4 and the corresponding leg of the bridge the bottom edge of cutting element 4 abuts the upper surface of base 10 of the bridge to provide vertical support for the cutting element in the embodiment shown in fig3 6 like reference numerals are used with like parts in the embodiment shown in fig1 and 2.