Cheap alternative to a center punch

When drilling flat surfaces drill bits tend to wander a bit. A center punch is be used to keep those wandering bits in check. What if you don't have a center punch you ask? Well here is a trick which uses common items laying around the shop. I used it while helping Tim with his truck rack and he said I should do an instructable for it. So recently while I was working on my own microwave transformer welder I found a perfect opportunity to snap a few pictures and write one up. Here we go.

You will need:
A Screw or a nail
A Hammer or other impact persuasion device
Something to drill

Step 1 The only step

Determine where you want to drill your hole. Then place the tip of the screw at that point. Next hit the screw/nail on the head until you make a dent. Finally drill to your hearts content free from wandering bits*
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*Really big bits will need a pilot hole but what better way to make sure your pilot hole is dead on than with a dent.