Instructables
Picture of Prepare to Drill Metal : How to Use a Center Punch
This is one of those 101 topics that I feel could use some exposition so drilling holes in metal can be a confident, well-informed, and efficient experience.

A center punch is a tool with a pointed end that makes a dimple in your piece of material right where you intend to drill a hole. 

A center punch mark accomplishes two things:

- It gives a physical resting place for a drill bit so it stays right where you want your hole to be
- When you begin drilling, the recess of the dimple relieves pressure from the flat tip of the bit (the "chisel tip" or the "web".) This prevents bending, chipping, breaking.

PLEASE:

- Consider center punching a REQUIREMENT for making holes in metal with drill bits
- Use a center punch for bits up to (arguably including) 1/2" in diameter.

For larger bits ( > 1/2"):
          - make a center punch
          - drill with a bit the size of your intended bit's chisel tip (this is called a "pilot hole")
          - drill with your intended bit.

For this demonstration, I'm drilling a hole in a piece of mild ("hardware store") steel. Well, in the interest of full disclosure, I'm making a corner bracket. :)

And, naturally, I did all deez workins at Techshop Detroit! www.techshop.ws
 
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padbravo4 months ago

Great picture! good closeup.

Pizzapie5002 years ago
Hehehe, I use an auto center punch :D

What is that thing?

enl_public1 year ago
re: "my mark is a smidge off"

The punch mark can be walked along the surface by tilting the punch. Light blow for the mark, walk it to the correct location with light blows if it is off, THEN heavier blow for full punch mark.
tholopotami2 years ago
Nice! Whoever has done even a little metal work knows that the preparation for drilling is not a trivial matter.

This is a trick I use which I learned from others and involves a hand (motorless) drill . Suppose the mark of your centre punch was a little off.. Then using the hand drill at a small declination from the vertical direction you work trying to shift the mark to the desired place pressing as you turn the tool. If you use the appropriate bit size the mark should be round and centred again.
embochner2 years ago
very informative thanks
rimar20002 years ago
Nice instructable.

When you need to make a hole of 1/4" or more whit a little accuracy, you can make before a littler hole, i.e. 1/8", obviously in the same place. That simple trick make easier to do the entire work. That is named "pilot" hole.