The standard provides maximum and minimum permissible variations from the specified thickness. These vary based on:
Imagine you are a stamping plant. You buy 100 tons of steel, and your tooling is designed to the 2017 flatness spec. However, your supplier has a dusty copy of the 1998 version. The 1998 standard is looser by 0.020". You certify the steel as "good," run it through the press, and break a $50,000 die. The lawsuit will hinge on which standard was cited in the purchase order. If you said "per AISI D100," you lose. If you said "per AISI D100-17," the supplier is liable. Aisi D100-17 Pdf
Always, always specify the year in your contract. Buckling and stability: