| 摘要 |
A spiral drill and a method to manufacture a spiral drill with two indexable inserts and two coolant channels (23, 24) wherein the coolant channels located in the holding shank part extend either parallel to the center line at different distances from said center line, or extend conically in relation to said center line, where the middle portion has been twisted while in heated condition to form spirally curved coolant channels (17, 18) and where the exit channels at the tip have been drilled after twisting, and where the exit openings (21,22) are located at different distances from the center line. <IMAGE> |
