Compound piece ream bit of cascaded scraper of major diameter

The utility model relates to a compound piece ream bit of cascaded scraper of major diameter, including the drill bit body with set up in the starter of drill bit body lower extreme, be provided with a plurality of wings body on the drill bit body, the wing body is the stairstepping structure. The beneficial effect of the utility model show: the utility model provides a compound piece ream bit of cascaded scraper of major diameter can directly creep into drilling, solves the problem that tooth, inefficiency were easily broken off with the fingers and thumb to general drill bit, the cascaded wing body is provided with the flank, is fit for medium ground major diameter drilling construction, but high efficiency creep into, efficiency is that general drill bit is more than 2 times, for the probing trade provides novel drill bit in the drilling of medium ground construction major diameter, be fit for any deep drilling, wide applicability to manufacturing process is simple, its simple structure.