MOP steel

https://en.wikipedia.org/wiki/Eglin_steel
Yield is around 200,000 PSI, exceeding a Grade 8 bolt at 150,000 PSI. It accomplishes its strength with only 5% Nickel and lower amounts of other valuable metals, so the ingredients are cheaper than stainless and processing doesn't require a vacuum furnace except to achieve the highest properties.
The compressive strength of granite is given as up to 45,000 PSI. Single point carbide tipped chisels are recommended to carve it, carbon steel chisels for other types of stone dull in seconds on it. The rock drill rod I turned the jack adapter from is a broken and discarded end with the 3" drill bit still on. 1/2" carbide buttons worn hemispherical do the cutting/pulverizing, with compressed air removing the dust.
"Eglin steel can be welded easily" but machinability isn't mentioned. HSS cuts Grade 8.