Old Hardware Store Auction find, Can't figure out what they are.

Obtained these in an auction of an old hardware store that opened in the 50's and the second owner decided to close shop. They were in the bottom of a box with other misc stuff. Been searching and cannot figure out what they are. There are three sizes and they are numbered smallest to largest "1", "2", and "3" respectively. The smallest is about 6" long, the middle is 7-1/2" and number "3" is 9" long. They also have a casting stamp that sows the symbol that I see as the outline of the US Interstate signs but it has a capitol H in the center of it. They look like some type of wedge as the tapered end sharp as an ax would be and the opposite end looks like it might have been designed to be hit into place but the little hole with the slot is what is odd. The current store owner did not know what they were so I am guessing they were there when he took over in the early 80's (this place had a full basement just crammed full of stuff). Any knowledge that can be passed on about what these are would be greatly appreciated as I have several of each size and want to figure out if they hold more value as is or if I can do better to make something with them. One person said they looked kinda like a cutting blade used on some type of agricultural equipment.