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.
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:
- 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).