Indexable spade drill blade

摘要

The present invention relates generally to spade drills and more particularly to an indexable spade drill blade which is adapted to be clamped in the clamp slit of a boring bar or holder and which may be readily reversed so that an unused cutting edge may be brought into play for further boring when wear has taken place on the cutting edges. Essentially the spade cutting blade is formed with an eccentric to permit indexing and must be used with an appropriate boring bar or holder which has a shape such that the cutting point of the eccentric blade is brought on the shank center line of the boring bar or holder.