around the peripheral surface 16 of disc element 10 with these bit like elements 14 having compacts of hard wear resistant material 18 forming the forward working portion of bit elements 14 as can be seen in fig1 the peripheral surface 16 of disc element 10 may be a curved configuration such that bit elements 14 may locate thereon what is shown in fig2 is a view taken along line ii ii of fig1 which shows the bit element 14 having a compact of hard wear resistant material 18 becoming the forward working portion of bit element 14 further what is shown in fig2 is a slotted portion 20 formed through the rearward end of bit element 14 and extending forwardly toward the forward working portion of bit element 14 slotted portion 20 thereby forms dependent legs 22 and 24 and a locating surface 26 on bit element 14 locating surface 26 joins dependent legs 22 and 24 on bit element 14 with reference to fig3 what is shown therein is a cut away section of a side view of the bit element 14 shown in fig2 having a compact of hard wear resistant material 18 forming the leading edge of the forward working portion of bit element 14 the rearmost end of bit element 14 has slot 20 formed therein and locating surface 26 is shown having a curved configuration which is generally complementary to the curve of locating surface 16 of disc element 10 what is shown in fig4 is a view.