Some welding help.

I picked up a nice set of heavy forks for my TL150. I am in the process of making the mounting points for the forks. I used 7018 rod 5/32 running at 190 amps with a ranger 250. I did three thick passes and the welds looked good. I then tested the mounts by picking up the rear end of a 9000 lb we have at our shop. I was only using half the forks to see what would happen. About the time the fork lift was coming off the ground, the steel bar popped right off my forks.

Does it appear that I need to layer more welds, or is my bar not good steel? Or did i just over load the weld?

Thanks for your time..

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Some welding help.