Beating a child with an object other than your hand is illegal in most states. If not, all.
I think if it's constant "spanking" on the ass, leg, hand, or face for one mistake a child did is abuse.
On a related note when I was like 4 my mom kept slapping me across the face with her slipper cause I was throwing a toy around and it hit my baby brother on the head. I was sorry but she kept screwing me over.
:(