I see Lunsford uses Grade 5 Ti-6Al-4V which has a tensile strength yield of 128,000 psi and a Rockwell hardness of C36.
Grade 8.8 steel screws have a Rockwell hardness of C37 with a tensile strength of 170,000 psi.
Stainless screws have a minimum tensile strength of 70,000 psi, and are not rated for hardness.
I am showing aluminum screws are not rated for hardness or tensile strength.
Just an FYI for anyone wondering about the different types of fasteners for their buggies, and where it's best to use which type.