METHOD FOR FORMING HOLE-PROCESSED CASTS, CAST CASING, AND SCREW COMPRESSOR CASING

摘要

A method for forming hole-processed casts that performs hole processing with a drill (17) so that the hole communicates with a cored hole (12) comprises a casting step and a hole processing step. In the casting step, a cast (10) is made, the cast having the cored hole (12) that includes a flat inner wall face (15a), with the width of the position where hole processing is performed with a drill (17) being a second length (H2) resulting from adding a first height (H1) that is the manufacturing error range for the cast (10) to the diameter (D) of the drill (17). In the hole processing step, a through-hole (13) is formed by way of the drill (17) so that the inside of the cored hole (12) and the outside of the cast (10) communicate via the flat inner wall face (15a).