Patent ID: 7171871
Filing Date: 2007-02-06
Classification: B23B,B25B

Abstract:
1. A bit for removing a broken fastener having a direction of engagement, said bit comprising: a) an elongated shaft with a longitudinal axis, said shaft having a first end, and a second end, said first end terminating in a tip; b) a plurality of cutting edges extending radially from said tip, said cutting edges configured to cut into the fastener when the bit is rotated in a direction opposite to the fastener's direction of engagement, wherein each cutting edge defines an angle to the longitudinal axis of the bit; c) said second end of the shaft configured to be received by a chuck of a tool which provides rotational torque; and d) said cutting edges define scraping surfaces and wherein said surfaces comprise serrations, wherein each serration defines a crest and a gap and the crests of the serrations on a first cutting edge are aligned with the gaps of corresponding serrations on a second cutting edge and wherein said crests and said gaps lie at the same radial distance from the longitudinal axis.