How to Make Automatic Centre Punch

[diyfixman]

Automatic Centre Punch - When you have so much junk in the workshop that you don't really have to buy it, you can just build one with ease with the help of a simple spring and bolt.

[DIYer]

Thanks diyfixman! We've added your Automatic Center Punch to our Measuring and Marking category,
as well as to your builder page: diyfixman's Homemade Tools. Your receipt:

Automatic Center Punch by diyfixman

tags: punch

[Christophe Mineau]

Great ! That's an idea!

[desbromilow]

I have several of the "springtool" versions of this including several of their pin punches. the commercial version has a hammer inside the spring which delivers the blow, more than just the mass of the spring itself.( see

for examples)
For a DIY, this is great - the only thing I'd change is putting a hardened tip in the punch - for DIY, I'd drill a hole in the tip, and insert a concrete nail for the punch tip.
in the commercial offering, the centre punch version has a hardened tip which is TOUGH, whereas the rest of the tool is about grade 8 tough (marks with a file)

[neilbourjaily]

Just brilliant.

[desbromilow]

just watched the video I linked to - the guy calls out some of the tools wrong he confuses a prick punch with a centre punch, and snaps everything 3 times - one is usually enough.
I only linked it to show what a commercial spring tool looks like. if you're in Australia, the toolquip group have been clearancing them for a few months - mostly pin punches left, at $5 each. I bought up a few, and reground one to make another centre punch.

[Toolmaker51]

I agree with desbromilow; a hard tip will give better results over time.
Concrete nails are easily 55+ Rc, other materials come to mind too, in no particular order. For starters,
Broken Tap, end mill or drill shank,
Drill blank,
Tip of a deck screw
Paneling nail...
Drill blind pocket and set point with epoxy, anaerobic or cyanoacrylate adhesive. The small mass will heat easily and facilitate replacement.

[Jon]

Congratulations diyfixman - your Automatic Center Punch is the Homemade Tool of the Week!

This one wins on pure cleverness and simplicity! We can all build one of those from our junk boxes.

Some more good builds from this week:

Bench Vise by fawabros
Grinding Wheel Arbor by old_toolmaker
Tachometer by glens5
Grinding Wheel Dresser by ttmrj
Cutting Fluid Dispenser by celsoari
Mill Hand Wheel by celsoari
Automatic Water Dispenser by mariost
Mill Quill by engineer steve
Crosscut Sled Stop Block by Make Things
Chip Guard by machining 4 all
Gear Cutting Lathe Attachment by machining 4 all
Jigsaw Blade Handle by Mr.DK DIY
Support Roller by Kwandotechnic
Welding Positioner by bouboulas


diyfixman - you'll be receiving a $25 online gift card, in your choice of Amazon, PayPal, or bitcoin. Please PM me your current email address and gift card choice and I'll get it sent over right away.

This is your 2nd Homemade Tool of the Week. Here are both of your Homemade Tool of the Week winning tools. Congrats again

Bender by diyfixman

tags: bender

Automatic Center Punch by diyfixman

tags: punch

[mbshop]

Never seen a spring like that. I made my own that sorta work but not nice like the one being shown.

[diyfixman]

Thanks so much my dear friends, I just love this forum.