Open the chisel to find the smallest chisel with a rounded corner, then look at the largest chisel, it has dents with a rolled edge as if it would be used against a tree with a nail in it. It should be new but I don't see how there could be a bigger chisel. Either way, you can buy 4 packs of Stanly or Irwin at the hardware store for $4-5. Save here and go shopping!