Grade of steel used for implements?

[Sodo]

Yes overlapping below; using existing holes is better.

 

[Egon]

Yes, I am pretty happy with the robust construction. The limitation is that there are no shear bolts, which may be fine for frequently cultivated soil but a bit of risk for my use. My thinking, and the only option I can spot is to replace these two horizontal bolts with shear bolts.

Thanks, Gus
View attachment 435216

Shear bolts in those areas may case some frame twisting when one bolt breaks.

I'd suggest a layout where The plow arms are completely on the side with no framework above them.

I'd go with a welded on box tubing extension with fillets in the corners. Also add fillets to the three point arm extensions.