| 摘要 |
A masonry drill bit 1 having an active diameter of D, comprising a shaft 3 and a tip 5 for engaging a workpiece, the tip 5 including a central portion 11 extending ahead of an outer portion 13, wherein the central portion 11 has a width of at least 0.25D and is shaped to act as a chisel during percussion drilling, and wherein the outer portion 13 is shaped to cut a workpiece as the drill bit rotates. By virtue of the drill bit tip 5 configuration as described and claimed herein, a masonry drill bit 1 having improved performance is provided. <IMAGE> |
