Screw Punch math

I’ve had my Japanese screw punch (a.k.a. push drill, a.k.a. hole punch) for a number of years now and I super love it. It’s one of those things that will initially make you balk at the cost but once you own it, you’ll wonder what you ever did without one.

Japanese screw punch

The punch manufactured by Nonaka Mfg. Co. Ltd. is considered the best brand of this type of tool. According to their website, they invented the punch in 1977 and have been producing it ever since.

If you ever have trouble figuring out what size bit you need for a particular task, check out these handy resources:

Nonaka’s website:

  • 1.2mm = 1/16″ eyelet
  • 3.0mm = 1/8″ eyelet or rivet
  • 4.0mm – 4.5mm = 3/16″ eyelet or rivet

Volcano Arts’ website (scroll down the page to view):

  • 1.0mm = book sewing needle size
  • 5.0mm = screw post size

If you’re shopping for screw punch bits, you may find that most vendors sell the following sizes: 1.0mm, 1.5mm, 2.0mm, 2.5mm, 3.0mm, 3.5mm, 4.0mm, 4.5mm, and 5.0mm. FYI – there are two more sizes: 1.2mm and 1.8mm.

I was lucky enough to find those two sizes while shopping in Japan and I happily snapped them up. If you want to get your own, I found them for sale at Beyond Measure (in the United Kingdom) and Best from Japan (in Japan).

6 Responses to “Screw Punch math”

By Renee - 9 January 2019 Reply

I love my drill too!  It has punched a multitude of holes.  I believe I bought from Lee Valley tools. Wondering what to do when it gets stuck after hole drilling.  I can easily pull it out.  I’ve wondered if a drop of oil could help.  Any ideas?  Or is it just worn out?  I have replaced bits several times. Thanks 

By Elissa - 10 January 2019 Reply

Renee –

Do you mean that it gets stuck in the material you’re drilling? If so, how thick is the material? Perhaps you’re trying to get through too much?

I wouldn’t add oil because that could get on your material. I might try a few more pushes on the drill to see if it enlarges the hole a smidge and frees up the drill bit.


By Renee - 10 January 2019 Reply

When you push down it stays down but it isn’t stuck in paper. I take it out of paper and I pull so it returns to original length.  Does that make sense?  When you push it stays and doesn’t want to unscrew. Thanks.

By Elissa - 13 January 2019 Reply

Renee –

Hrm…I’ve never experienced that before. It does sound like it needs to be lubricated somewhere, but I’d worry about it transferring to your paper. If you add oil, use the drill on scrap material first to see if you can get rid of any excess that might get on your good stuff.

Let me know how it goes.


By Diane - 17 February 2020 Reply

Mine is doing the same thing. The shaft is scoring and there a fragments of brass on my paper sheets. I lightly polish the shaft with an extra fine emery cloth and make sure I wipe to remove any bits that might travel inside. This will get me partially through a project. purchased mine from Talas around the first of this year so it’s fairly new.

By Elissa - 10 March 2020

Diane –

I’m not sure why bits of brass would be coming off – that’s not good! Try contacting Talas and see if they have any advice/tips for you. Report back if you hear anything useful!


So what do you think? I'd love to know!

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