[Mark was here]

A bolts strength is determined by it's diameter, and thread engagement should be a minimum of one and a half times the diameter. If someone wanted to discuss bolt strength, by discussing the length alone, I would question why the question in the first place.

[gas0linealley]

Would you say that one and a half times the bolt diameter would suffice for embedment in concrete with epoxy bonding?

Of couse not. Obviously, bolt length is a factor in such a design.