5/16" Core Bit for Stone & Lapidary

THIS IS A DROP SHIPPED OR SPECIAL ORDER ITEM. PLEASE CONTACT OR LEAVE A NOTE IN THE COMMENTS BOX REQUESTING ESTIMATED WAIT TIME FOR SHIPPING This core bit is ideal for glass, stone and lapidary purposes. This bit is intended to drill cylindrical holes into stone. The measurements are as follows: A-5/16", B-.25", C-1 1/2" (Drilling depth 1 1/4"), D-.25", Nut- 5/8"-11.