How can I tell if a padlock is hammerproof?

Question

And don't say to smash it. That would be a waste.

Answer 1

A good way would be to see if it has a common brand name on it , the usually are more expensive , and will take a knock , however to be certain you would be better buying a new one that is guaranteed especially if it protecting something of value

Answer 2

Read the packet. if you don't have the packet look at one in a shop

Answer 3

As they say the Proof is in the Eating, You will have to Buy or Steal The Brand of Padlock that you want and Batter  it with various types of Hammer, from small to large, ending in an Sledge Hammer. If you are satisfied then go out and buy a New Padlock of that type.