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