2" x 2" square tubing with a .120" wall will not make for much of a fork. It would probably be good (safe) for 200 lbs or so about 18 inches beyond the front edge of the bucket.
If you want forks that can handle roughly 800 lbs (per two forks) use 2" x 2" x 3/16" wall.
For 1200 lbs use 2" x 2" x 1/4" wall, for 1600 lbs use 2" x 3" x 1/4" wall, and for up to 2000 lbs cpacity use 2" x 4" x 1/4" wall steel tube.
Thes numbers mean nothing if the rest of your design is not done correctly, or if you have bad welds! Attached are some pics of a few forks I have built in the last few years. I had one set of 2000 lb forks come back.....they had been modified to fit a John Deere comercial backhoe/loader, and they lifted a 4500 lb pallet of lanscape blocks. These forks were 2" x 4" x 1/4" wall, and they did not break with this load, but the clamp mechanism bent. I repaired the forks and explaining what the rated capacity meant....and sent him on his way. (I have good insurance!)
Jim