Super Simple Center Punch

I have an automatic center punch in my workshop but it never quite delivers the right hit and sometimes it even misses to hit at all.

I wanted to make another so I can have something that can deliver more impact when needed so I decided to use an old car engine valve that I've got from a car service for free.

The valve is made out of a strong alloy so it will be perfect for the job.

To make the cone, I've seen many people cutting off the valve head. However, I didn't want to do that since the head will be a perfect and wide surface for hitting.

Supplies

Tools and materials used in the video:

• Automatic Center Punch - https://s.click.aliexpress.com/e/_ApGIxt
• Cordless drill - https://s.click.aliexpress.com/e/_AfEvlZ
• Disk and Belt Sander - https://s.click.aliexpress.com/e/_9xEDSj
• Torch lighter - https://s.click.aliexpress.com/e/_9uQ5gB

Alternative links on Banggood:

• Automatic Center Punch - https://www.banggood.com/custlink/Dmvd88jAuw
• Cordless drill - https://www.banggood.com/custlink/mKKR9iOzmG
• Angle Grinder Sander - https://www.banggood.com/custlink/vmGESSLMvH
• Butane torch - https://www.banggood.com/custlink/KGmdSioqDa

Step 1: Secure the Valve for Spinning

Since I didn't want to cut off the head of the valve, I had to find a way how to secure it in my drill so I can grind off the tip.

My first idea was to glue a piece of hot glue stick to the head, so the glue stick can be then mounted in the drill chuck.

I've used a propane torch to heat up the valve but since the valve was cold, the glue did not stick at all.

Then, I pre-heat the valve as well and this time the glue was holding, at least for a while thou.

As soon as I started grinding the tip of the valve, the glue failed, and I needed a plan B.

I grabbed a piece of steel wire and wrapped it around the valve, making sure to leave at least three tabs around the head so I can tighten it with pliers.

The resulting pin was then secured to the drill chuck and this worked perfectly.

Step 2: Grind the Punch Cone

To grind the cone, I've used my disk sander while simultaneously spinning the valve in my drill.

This made sure that the grinding is even on all sides and that the cone is not tilted to one side.

Since the grinding induces heat to the valve, I used some water to periodically cool it off so it stays strong.

Step 3: Enjoy!

A center punch is a must in any workshop and it only takes an hour to make one.

Check any of your local engine repair shops and I'm sure that they will be happy to give you a used valve for free.

If you liked this Instructable, make sure to also check my other ones and subscribe to my YouTube channel.

Cheers and thanks for reading.

Comments

[robertsteel]

Quote "the head will be a perfect and wide surface for hitting."
After having and using one in my punch dish for nearly 40 years I can tell you its the most difficult punch I have to hit squarely . I keep it in case I need to hit it with a copper hammer or wood mallet only.

[taste_the_code]

Hmmm based on the use so far, I did not have that issue. I guess it might be a matter of how it is held?

[dhaykus0418]

We still have one like this in my 88 year old fathers tool box that he made many decades ago. We still pull it out for use occasionally.

[taste_the_code]

NIce! Thanks for sharing!

[Nebulosa]

I made one of these many years ago. The steel that a valve is made out of is very hard so it will punch a nice mark in a lot of materials. The one thing I hated was the way the shaft would vibrate in my fingers when I hit it with a hammer. It was actually painful. I'm not sure why it did that but I much prefer using a "proper" center punch.

[taste_the_code]

Maybe it is because the valve is quite thin so the impact bends it a bit. Mine feels OK so far but I would need to put it into more serious use to see how it behaves.