Frank, how are you mounting the square stock in your handle, turning it round? A pic would be nice.
Went to our local recycling yard and got a 3' 4" piece of the 3/8" square for $2 and picked up 1 x 30" of 2024 T6 for $3 to make some handles.
Since you asked, I did spend a few minutes on the grinder rounding the square stock prior to pounding it into the hole in the handle. This handle is made from a hunk of scrap figured hard maple. The ferrule is a copper coupling I bought and added almost $1.00 to the total cost of the tool. BTW, the overall length is 20". The steel shaft is 9" exposed. This might be a little too long for some folks taste but I believe it will make this a very versatile tool. You don't like, get out hacksaw.
Good for you finding that steel stock. Scroungers rule.
Daniel, thanks, again, for the good tip on the steel. Even though I wasn't thinking along those lines, the place I buy my steel sells to guys who will be welding. I used to buy there when I needed to repair or fabricate stuff for my farm equipment.