METHOD OF DRILLING HOLE FOR STEEL PIPE IN CASTING AND PIPE IN CASTING FOR HOLE DRILLING

摘要

PURPOSE:To prevent development of burrs in hole drilling and simplify work process, by plugging a casting plug beforehand at a prescribed position in a pipe to be placed in casting and drilling a hole in the pipe through both tne casting and the plug after casting. CONSTITUTION:Screw holes 12 are pierced in a pipe 11 at the positions where holes are pierced after a casting with the pipe 11 is cast. The holes 12 have a diameter larger than that of said holes. Casting plugs 13 are screwed in the holes 12. The pipe 11 in this state is placed in the mold in which a casting such as cylinder block, etc. is cast. Holes 15 drilled through from the outer face 14a, so as to pierce through the plugs 13. Because the drill holes 15 end at the casting plugs 13, less drilling burr develops at the hole ends in comparison with holes through and ending at steel.