Separation type hole saw

A separation type hole saw, includes: a hole saw (3); a hole saw mounting metal fitting (2); a shank (5); a spherical body (13) inserted to the hole portion (12); an annular spring (14) inserted to the annular groove (15) and urging the spherical body (13) so that the spherical body (13) presses the fitting convex portion (2a) of the hole saw mounting metal fitting (2), thereby preventing the fitting recess portion (5a) of the shank (5) from being taken out from the fitting convex portion (2a) of the hole saw mounting metal fitting (2) due to the pressing operation of the spherical body (13); a center pin (6) inserted to a center portion of the shank (5) and guiding the hole saw (3) at a time of drilling a material in which a guide groove (19) is formed in an outer periphery of an end portion of the center pin (6) inserted to the shank (5); and a fitting member (22) provided in the shank (5). The fitting member (22) is fitted to and detached from the guide groove (19), whereby the center pin (6) is fixed to the shank (5) and is freely detached from the shank (5).