ASTM Standard Needed

If those are legitimate fastener grades, the fastener manufacturer should be aware of them. I don't recognize them as ASTM or SAE grades but there are several other MIL, ANSI, ISO, AAR, Federal, etc. standards that may apply. As I recall, plow bolts are covered by ANSI B18.9.

You had a reason for specifying those grades, recommend you go back to your customer or source for a lead to the standards organization.

Might also check IFI (Industrial Fasteners Institute).

These are ISO standards. The 12 and 10 are 1/10 of the minimum UTS of the material in kgf/mm², the 9 is 1/10 of the ratio of minimum yield stress to minimum UTS, as a %. So minimum UTSs are 120 and 100 kgf/mm², and minimum yield stresses are 108 and 90 kgf/mm², the

120 kgf/mm² = 170680 psi = 76.2 ton/in²

100 kgf/mm² = 142230 psi = 63.5 ton/in²

108 kgf/mm² = 153610 psi = 68.6 ton/in²

90 kgf/mm² = 128000 psi = 57.2 ton/in²

These are high-tensile bolts, only stronger grade in data I have is 14.9. As others have pointed out, this strength is likely to be used for a good reason, and I wouldn't risk a lower grade without being sure it's OK.