or burning the wood. Set Includes: Depth stop collar (2) Depth stop locking rings (6) coin size forstner bits Hex head key wrench for depth stop ring adjustment. This product is one forstner bit the size if a US one dollar coin. I mistakenly thought by all of the photos that this was for a set of six bits in a wood box. $16 for a set. Coin Sized Forstner Bit Set. Reviews. 6 Piece Set makes perfect-sized mounting holes for every coin in your collection!