Can't tell what kind of tires?

[rowtohoe]

Hello.  I am an every day reader of the forum, but seldom write. I am trying to sell (2) 18.4 x 34 tires that came off of my skidder. They still hold air, but are wore so bad that I cannot read the lettering. I can see Firestone, but no more. Everyone who is interested wants to know if they are forestry tires. And I cannot tell for sure. Is there any other way to know for sure? Thanks

[ga jones]

The thickness of the side wall. The bead is also thicker than an ag tire

[coxy]

the tread on a forestry tire is also bigger/thicker say 31/2 wide the other will be 11/2-2 wide     if I said this right  ;D