many different insert configurations could be used provided they were capable of assuring the relationships discussed above the subject invention preferably incorporates an insert having the configuration best seen in fig5 through 8 this particular insert configuration allows the insert to be mounted in the drill in a retaining pocket 40 machined in the end groove 16 and having a bottom wall and a pair of side walls which join the bottom wall at a 90 u00b0 angle this 90 u00b0 angle relationship permits the insert to be rigidly locked in the pocket through the use of a simple removable connecting means such as a screw 42 additionally the top surface of the insert shown can join the bottom surface of the flute 17 with a smooth transition for proper chip flow in the description of the indexable insert which follows terms such as upper and lower will be used merely for the sake of clarity these terms are not however to be considered as limiting the manner in which the indexable insert is used or related to the drill shank or recess 16 referring in particular to fig5 through 8 the insert 40 is shown as comprising a solid unitary body 46 of any hard material suitable for cutting tools such as tungsten carbide or the like in general the body 46 includes upper and lower spaced generally parallel faces 48 and 50 the faces 48 and 50 are joined about their peripheral edges by vertically extending opposed pairs of side walls 52 and 54 respectively as shown in fig5 and 6 the.