Just want to jump in and should have earlier but been very busy. LG manufactured tractors are not cast iron as previously stated. All the LG/LS tractors are cast steel. Tensile strength as I understand it is 41kg squared per cm or mm. I really don't understand it but I believe it works out to 58,000 lbs. per square inch on all castings on the LG/LS tractors.
How do I know this? Well, I had a customer come in last year who is a mechanical engineer and he wanted to know tensile strenght and I told him I had no clue but would find out. I personally know the design engineer of the LG/LS tractors in S. Korea and I emailed him and he sent back the answer. I forwarded the engineer and he and his sister came in the next day with a cashiers check and bought the tractor. He was impressed anyway.
In any case, this is what I know the castings to be.
Thanks,
Maka