Every 20 base STR, Atk + 10, POW + 2, CON + 2.
If the enchanted equipment is grade D, P.Atk + 6, increases melee physical damage by 6%.
If the enchanted equipment is grade C, additional P.Atk + 9, increases melee physical damage by additional 10%.
If the enchanted equipment is grade B, additional P.Atk + 12, increases melee physical damage by additional 14%.