Patent ID: 8393830

Claim:
A cylindrical rotating tool with internal fluid passage, said tool comprising a major diameter portion having at least one internal fluid passage for allowing coolant to flow, a minor diameter portion provided in front of the major diameter portion, and a tip attached to the front of the minor diameter portion, said tool having a cylindrical shape centered about a central axis line, wherein when seen from behind the central axis line, an inner circumference of an outlet of said internal fluid passage intersects with an outer circumference of said minor diameter portion, at the site of said outlet, a notch is formed on an outer circumferential surface of said minor diameter portion, said notch has an inclined portion provided at the front of said outlet, said inclined portion is formed obliquely so that the distance from said central axis line to said inclined portion on further forward of said minor diameter portion becomes larger than the distance from said central axis line to said inclined portion on a closest position on the entire circumference of said outlet to said central axis line, and said inclined portion guides a partial flow of said coolant, gushing forward from said outlet, outward in a radial direction of said minor diameter portion.