Interesting project and maybe designed for a specific task. You have rare skills and ambition. No mention of steel grade. Mild steel may work on small tractors but not on larger, tlb, or skid steer. Been using/abusing grapples for decades. I’m a Pretty good fabricator, but can’t compete with high strength steel manufacturers. A grapple made of T1, 50-60 steel would have be twice as thick, twice as heavy and not abrasion resistance if made of mild steel. Would really hurt performance.