The angle between the bottom surface 35 of the insert 21 and {HEAD ~ the sidewalls} 59 of the insert is typically equal to or greater than the angle between the bottom surface 55 of {TAIL ~ the recess} 53 and the sidewalls 57 of the recess 
The angle between the bottom surface 35 of the insert 21 and { HEAD ~ the sidewalls } 59 of the insert is typically equal to or greater than the angle between the bottom surface 55 of { TAIL ~ the recess } 53 and the sidewalls 57 of the recess
OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH HEAD HEAD HEAD HEAD HEAD HEAD OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH TAIL TAIL TAIL TAIL TAIL TAIL OTH OTH OTH OTH OTH OTH OTH OTH