in fig1 a cutter tooth 1 is shown inserted in its position in the partly sectioned fragmentally drawn holder 2 . the tooth 1 is inserted in its position in the direction indicated by the arrow a and the tooth is removed in the opposite direction . the tooth 1 thus is inserted in a groove in the holder . on both sides of the groove the holder has a bead 3 whichs fits into a corresponding groove in the tooth , while the tooth on both sides has a bead 4 which fits into a groove in the holder . the beads and the grooves and a contact surface between the rear edge 5 of the tooth and the stopping edge 6 of the holder determine the position of the tooth in all directions except the direction of insertion and removal . on the underside of the tooth , facing the holder , there is an opening 7 into which the securing member can be inserted . in the variant shown in fig1 - 3 , this opening is delimited at its inner end by a cleat 8 having a stopping edge 9 facing the securing member , and at its outer end by a somewhat lower cleat 10 , the inner edge of which to a certain extent is obliquely chamfered at 11 . in the holder 2 there is also arranged an opening 12 opposite opening 7 , which is delimited at its outer end by a blocking edge 13 . a through hole 14 runs through holder and opening 12 , transverse to the longitudinal direction of the opening 7 . the upper edge of the hole 14 is at least as high up as to be on a level with the upper edge of the blocking edge 13 . thus , openings 7 , 12 define an open - mouthed recess within which the securing member is placed . the securing member itself comprises two elongated , longitudinal edge members or parts 15 , 16 , made of metal , which are held together by an elastic middle part or body 17 . the joining of the middle part and the two edge parts is achieved by gluing , or in some other known way . the middle part can be made of rubber or some other elastic material . both of the edge parts have a rectangular cross section . one edge part 15 , which can be somewhat thinner than the other edge part 16 , preferably has bent ends 18 , 19 shaped to fit within opening 7 . the other , thicker edge part 16 comprises an elongated portion which extends beyond body 17 toward the mouth of the opening 7 and has two transverse grooves 20 , 21 , separated axially from each other . grooves 20 , 21 reduce the thickness of edge part 16 and provide buckling locations . of these grooves , groove 20 , nearest the inner end 22 of the edge part 16 , is applied on the side of the edge part facing the elastic middle part 17 . the groove 20 has a flank 23 located transverse to the inner end 22 of the edge part 16 , and a sloping flank which angles upwards so that the groove ends just above a transverse flank 24 of the second groove 21 . this second groove 21 is applied on the other side of the edge part 16 with its transverse flank 24 facing the flank 23 . the two grooves 20 , 21 thus bound a slightly angled , narrower connecting part which must transmit a force acting on the outer end of the edge part 16 . if edge part 16 is compressed in its longitudinal direction , it will buckle , with the result that a portion of edge part 16 will move away from edge part 15 and thereby provide a securing in the longitudinal direction of the member . if the distance between the inner end 22 of the edge part 16 and transverse flank 23 of the nearest groove 20 is made somewhat less than the distance between the stopping edge 9 and the blocking edge 13 , the buckled configuration shown in fig1 will be obtained when the securing member shown in fig3 is influenced by one or several heavy blows in the direction of the arrow b . the edge part 16 of the securing element will then be forced forwards so that it will come into contact with the stopping edge 9 on the tooth . squeezed between the stopping edge 9 and the force influencing the outer end of the edge part in the direction of the arrow b , the edge part will be buckled at grooves 20 , 21 and will be forced on a level with the first groove 20 away from the other edge part 15 and down into the recess 12 , whereby it will come into contact with the blocking edge 13 . thus , the edge part 16 and the grooves 20 , 21 cooperate to provide a means for permitting an edge member to buckle into contact with the blocking edge when the edge member is subjected to compressive stress . the obliquely set part of the buckled out edge part 16 between the stopping edge 9 and the blocking edge 13 then provides for very firm securing , at the same time as the elastic middle part 17 of the securing member eliminates any play that might impair the functioning of the tooth . this latter function is best achieved if the middle part is made somewhat wedge shaped , in accordance with the variant shown in fig2 . as shown in fig1 and 5 , with a carefully adapted form of the recess 12 , combined with apporpriate dimensions of the securing member , the shallow part of the recess 12 will act as a further support point for the buckled out securing member . by forcing a drift through the opening 14 , the edge part 16 can be straightened out for removing the tooth and the securing member . as will be noted from the figures , in the normal case , and when not subjected to any load , the front edge 18 of the edge part 15 appropriately extends somewhat farther out in front of the front edge 22 of the edge part 16 . the front edge 22 should moreover preferably be somewhat obliquely chamfered towards the free outer side of the edge part . when the edge part 16 is buckled out by means of one or several heavy blows with a hammer , it will thus first be forced forwards owing to the prestressing of the elastic middle part until its front edge 22 comes into contact with the stopping edge 9 and the buckling out will take place only thereafter . as the elastic middle part 17 strives to resume its original form , the front edge 18 of the edge part 15 will be forced against the stopping edge 9 of the tooth at the same time as the buckled out section of the edge part 16 is forced against the blocking edge 13 of the holder 2 . it is thus only at more extreme loads that the stopping edge 9 will be displaced into direct contact with the front edge 22 of the edge part 16 , but the movement of the tooth in this direction will then be totally blocked , as the buckled out part of the edge part 16 gives a metallic connection between the cleat 8 made on the tooth and the stopping edge 13 in the holder . fig1 - 3 show a variant of the securing member according to the invention in which the elastic middle part 17 ends on a level with the first buckling groove 20 . the edge part 15 then also has a length which does not to any major degree exceed the length of the middle part 17 . as shown by fig1 and 3 , the tooth 1 is provided with the cleat 10 , which defines the outer end of the space for the securing member . cleat 10 is shaped so that there is space for the edge part 16 between the cleat and the holder . the cleat 10 thereby prevents the outer portion of the edge part 16 from being bent upwards when blows are applied to cause buckling . in the embodiment shown in fig4 and 5 , the elastic middle part 17 and the edge part 15 without buckling grooves extend outwardly to be on a level with the outer edge of the tooth 1 . the cleat 10 is omitted , but the outer bent down edge 19 of the edge part 15 has been made so long that it performs the function of the cleat 10 by preventing the outer portion of the locking part from being bent upwards during buckling of the securing member . thus , the securing member shown in fig1 - 3 must be set in place at the same time as the tooth , and it is therefore an advantage to have it joined to the tooth , while the securing member according to fig4 and 5 is inserted in its place afterwards . the securing member can , for instance , be fastened to the tooth at the factory by means of gluing , or in some other appropriate way . by making the edge parts 15 and 16 of the securing member with different widths , and in the corresponding way adapting the width of the opening 7 and the recess 12 to these edge parts with different widths , the securing member easily can be prevented from being inserted the wrong way around . this applies particularly to the variant shown in fig4 and 5 .