The overwhelming factor is weapon quality, so let's look at the other stuff first.
Strength is not capped, so technically there is no limit. We'd have to pick an arbitrary number. The ridiculous champions of
Headshoots had Strength of about 20, so we could go with that.
The berserk and charging bonuses max at 5 and 4, and dwarf size is 6, so OTHER STUFF goes from 6 (normal non-Strong dwarf) to 35 (berserking, charging, insaneo-champion) at the extreme high end. Note that I'm adding in the dorf's size because we're assuming the creature is larger.
So, weapon quality. Let's assume a hammer (120), and increase quality and material at the same time:
Wood/silver/etc. Hammer = 120*0.5*1.0/10 = 6
Copper -Hammer- = 120*0.66*1.2/10 = 9
Bronze +Hammer+ = 120*0.75*1.4/10 = 12
Iron *Hammer* = 120*1.0*1.6/10 = 19
Steel ≡Hammer≡ = 120*1.33*1.8/10 = 28
Adamantine ☼Hammer☼ = 120*5.00*2.0/10 = 120
So our berserk, charging, Ultra-Mighty+15, adamantine ☼hammer☼-wielding dwarf will be unable to damage a (35+120) Size 155 creature through the normal damage formula.
Our normally Ultra-Mighty champion with a steel ≡hammer≡ will be unable to normally scratch a (11+28) size 39 creature. Dragons right now have size 24.