Patent ID: 9132534
Filing Date: 2015-09-15
Classification: B25B

Abstract:
1. A screwdriver bit, comprising: a connection portion; a narrow neck portion having a rod shape and defining a uniform diameter; a driving portion having an operation end is arranged at a front end of said driving portion, an effective working segment disposed on a front end of the operation end, and a reinforcing segment, wherein said diameter of said narrow neck portion is larger or equal to a length of said effective working segment; a first tapered transition extended from said reinforcing segment of said driving portion to said narrow neck portion, wherein said first tapered transition is an arc taper defining an arc surface extended between said driving portion and said narrow neck portion; a second tapered transition extended from said connecting portion to said narrow neck portion, such that said narrow neck portion is extended between said first tapered transition and said second tapered transition, wherein said second tapered transition is a straight taper defining a flat surface extended between said connecting portion and said narrow neck portion, wherein a maximum outer diameter of said effective working segment is no less than a total length of said narrow neck portion, said first tapered transition, and said second tapered transition, wherein a length of said narrow neck portion is not larger than the maximum outer diameter of said effective working segment, wherein the length of said narrow neck portion is 3 mm to 6 mm.