BI center bit is used for reaming hole bottom, the model No. likes 5 7/8"*7 1/2"*4 3/4" or just 5 7/8"*7 1/2" as the third diameter is not important.

5 7/8" is the passing through diameter, 7 1/2" is the reaming diameter, 4 3/4" is the diameter of front bit.

We can produce both matrix body and steel body BI center bit, the cutters could be diameter 8mm, 13mm, 16mm, 19mm, blades quantity ranges from 3 to 8.