Patent ID: 9539711
Date: 2017-01-10
CPC Classifications: B25B

Claim:
1. A bit for removing damaged screws comprising: a shaft portion and a head portion connected to the shaft portion, the head portion including a middle axis and being provided with a tip section and a threaded conical section connected between the tip section and shaft portion, the tip section including a vertex point, an outer peripheral surface of the threaded conical section defining an angle with respect to the middle axis, the threaded conical section expanding toward the shaft portion, and being a conical structure with a reverse thread, the bit being characterized in that; the head portion is provided with two symmetrical scraping portions extending continuously from the tip section to the threaded conical section, the two scraping portions each include a first scraping surface, a residual portion and a second scraping surface, the residual portion is a structure formed at a connection where the first and second scraping surfaces are connected to each other at an angle, the first scraping surface intersects with the tip section, the threaded conical section and a first connecting surface of the residual portion, a first scraping edge is formed at a position where the first scraping surface intersects the tip section, and extends between the vertex point and the threaded conical section, the second scraping surface intersects with the tip section, the threaded conical section and a second connecting surface of the residual portion, a second scraping edge is formed at a position where the second scraping surface intersects the tip section, and extends between the vertex point and the threaded conical section.