bushes to secure this position if necessary then when fastening bush 72 is clamped against the body of the plough body intermediate element by means of the fastening screw 74 the annular collar could have a small air gap in relation to the top limb alternatively the annular collar 71 could press by means of its lower annular flange against the top surface 112 and through tightening of the fastening nut 77 this mounting position can be additionally secured against loosening in order to anchor the screw head 75 of the fastening screws 74 on the plough body intermediate element 155 a top surface 162 is provided extending above the locking projection 156 and having respectively one blind hole 163 per fastening device 70 and a milled out groove 164 into which the screw head 75 can be inserted preferably so as to be secure against rotation as shown in particular by fig4 and 5 is provided close to the base of the blind hole 163 in order to demount the bit strips 111 it is necessary either first to remove the fastening bushes 72 or the entire bit strip 111 is moved transversely relative to the direction of movement or direction of excavation of.