Thanks,i guess i have now all the knowledge,just have to put in praktice somehow.About the material- am i wrong with the old drills(hss)?I have some,18-25 mm(about0.5-1""),but i've red about the heat treating,wich doesnt seem easy.(though i made one,even if not the proper way,but it still vorks).Is it reason experimenting around,or rather leave it.An old file i have as well,for triing