# How can I cut a thin (1mm) sheet of stainless steel with high precision?

I have a circular puck of stainless steel that is 9.5 mm in diameter. In the center, there is already a 5 um pinhole. My objective is to basically cut the steel along the dotted line, approximately 0.5 mm from the pinhole. Can you advise on what techniques to can make this cut precisely?

The reason I want to do this is to be able to align two of these so that I can have 2 pinholes that are ~1 mm apart from one another, as in the following image.

• You say "centered line", but I'm seeing from the image that the line is actually off-center, correct? Also, what is your definition of "high precision"?
– Wasabi
Mar 14, 2016 at 16:34
• @Wasabi Sorry I meant to say "dotted" line. I edited the question to reflect that. My definition of high precision is that I want it to be cut 0.5mm += 0.25mm from the pinhole. In other words, as long as the pinhole is intact and I can align two pinholes together I am happy. :)
– ArKi
Mar 14, 2016 at 16:44
• Do you have any restrictions on the type of machinery you can use to perform the cut? Because if not, a machine shop has plenty of tools to do the cut precisely enough as outlined the the answers. Mar 16, 2016 at 16:16
• I'm puzzled as to how the poster got a 5 μm hole, that is 1000 μm long, in stainless? Even laser drill will not give that. Jun 9, 2021 at 7:39

Calling a small disc that is 9.5 mm DIA and 1.0 mm thick "a thin sheet of steel" is a bit of a stretch.

Any machinist would simply clamp the disc in a suitable vise and mill away the unwanted part. Precision would be a couple orders of magnitude better than your requirement.

If you have patience and only need a small number of them done, a pair of pliers and a grinding wheel could accomplish the same thing.

• Ditto vise and coarse/fine files, probably faster than you could set up the mill. Mar 15, 2016 at 18:07

The tool I would use is metal cutting scissors (or Snips). It's remarkably easy to get a straight cut with these after a little practice. I would first make a cut far from the line (somewhere in the area you're going to discard), to get a feeling for a particular tool cutting steel of a particular thickness.

With some experience it is possible to cut as close as 1mm to the line, which reduces the amount grinding work needed.

• but it does the job but seems to create a big problem: you end up with an bended sheet of metal youtube.com/watch?v=BO3O5OBXIks (don't know if it's avoidable, or if there is a way to fix it) Sep 15, 2019 at 13:29

Probably the simplest way is to cut it a few mm oversized and grind or file off the excess.

I would say that 0.25mm is not very difficult to do.

You can use Water jet cutter to be really accurate or if you don't have this possibility, you can simply use a mill or CNC with specific drill.

CNC Milling should be precise enough (0.01 millimeter accuracy).

• Do you have any backup documentation to support this? Also, I assume that CNC accuracy depends on the quality of the machine. Mar 19, 2016 at 16:08