The lance 3, wherein {HEAD ~ the opening width} in {TAIL ~ the circumferential direction} is about four to eight times larger than the wall thickness of the webs in the circumferential direction 
The lance 3 , wherein { HEAD ~ the opening width } in { TAIL ~ the circumferential direction } is about four to eight times larger than the wall thickness of the webs in the circumferential direction
OTH OTH OTH OTH OTH HEAD HEAD HEAD HEAD HEAD HEAD HEAD REL TAIL TAIL TAIL TAIL TAIL TAIL TAIL OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH