The shank diameter is 1/4",the cutter bores a 3/8" diameter hole.
Yes, I have and it cuts a much cleaner hole than a drill bit, drill bits cut oval shaped circles in aluminum and the forstner bit cuts alnost perfect circles, wont last very long though maybe 8 cuts into 1/16 thick alluminum 7075 or 6061.
Hello William, thank you for your question and interest in Diablo accessories. The Shank length for all of our Forstner Bits is 2.8 inches. I hope this helps. Thanks.
The length is 6.75''.