{TAIL ~ The edges} of the slots are lined with upstanding flanges which are sharpened to form {HEAD ~ cutting edges} 
{ TAIL ~ The edges } of the slots are lined with upstanding flanges which are sharpened to form { HEAD ~ cutting edges }
TAIL TAIL TAIL TAIL TAIL TAIL OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH HEAD HEAD HEAD HEAD HEAD HEAD