On {HEAD ~ the outer peripheral edge} of the flange 11a are formed {TAIL ~ an engaging edge 11e} and a cutout 11g 
On { HEAD ~ the outer peripheral edge } of the flange 11a are formed { TAIL ~ an engaging edge 11e } and a cutout 11 g
OTH HEAD HEAD HEAD HEAD HEAD HEAD HEAD HEAD OTH OTH OTH OTH OTH OTH TAIL TAIL TAIL TAIL TAIL TAIL TAIL TAIL OTH OTH OTH OTH OTH