{HEAD ~ A side ridge line} 13 of the blade portion 12b forms {TAIL ~ a cutting edge} 
{ HEAD ~ A side ridge line } 13 of the blade portion 12b forms { TAIL ~ a cutting edge }
HEAD HEAD HEAD HEAD HEAD HEAD HEAD HEAD OTH OTH OTH OTH OTH OTH REL TAIL TAIL TAIL TAIL TAIL TAIL TAIL