Jewelry Disk Cutter

Have you ever tried to saw out a perfectly smooth-edged circle in a sheet of metal?

If you have, you will know there are some inherently difficult aspects of that activity.

For one, getting a perfect circle marked out requires either a round object in the appropriate diameter and a scribe to trace around the object or, even better, a good quality drafting compass.

Once the circle is marked, sawing it out perfectly is not easy as you will have to constantly change the angle of the cut to take you all the way around the circle without creating a jagged edge. This is done either by moving the saw following the line around or by keeping the saw in the same place and turning the metal instead.

Either way requires a fair amount of saw control and a very steady hand. The next challenge is if you want to create a “washer,” i.e. a round piece of metal with a round hole in the center. The tricky part of the washer is to make sure the edge is the exact same width all the way around the circle.

You get the point. Circles, spanners or basically anything round are not exactly the easiest objects to create with a saw.

This is where the circle cutter (or disk cutter as they are often called) comes into the picture. The disk cutter is basically two heavy blocks of metal that can be separated to clamp around a piece of metal. The blocks have perfectly aligned holes in various sizes machined through both blocks. Each hole has an accompanying “stamp” or cutting dowel that fits exactly into the hole in the block. The edge of the cutting dowel is sharpened and sometimes on a slight angle so when it’s inserted into the hole with the metal clamped in between the heavy metal blocks it can be hit with a mallet or a heavy hammer thereby cutting a perfect circle out of the metal.  Phew, lots of words to describe this:

Jewelers Swanstrom Disk Cutter 02

All the disk cutters comes with multiple holes and cutting dowels in sizes ranging from a few mm to several cm, normally presented in some type of organizing holder typically made from hard rubber, plastic or timber.

I did a lot of research when I was hunting for one for my workshop. Here is what I took into account when deciding which to go for:

Quality: It goes without saying that I was not going to choose some flimsy badly-machined high tolerance device in a poor quality metal (read: cheap Chinese-o).

Metric or imperial: This is always such a hard question when brought up in a country where measurements are in both metric and imperial. I concluded that the exact measurements of the disk sizes were not actually all that important as long as I had a full range of sizes from super small to large.

Range of disk sizes: As mentioned, I wanted something with a broad range of disks sizes.

Cutting ease and cut quality: It would make no sense to have a tool that creates a circle with an edge that is just as uneven as what could be created with a saw or a cutter. That would require a large whack with a 20kg mallet to make it through a 1mm piece of silver…

Storage when not in use: It was important to me that the device came with a neat storage setup either in timber or rubber so all parts were collected in one location and it was easy to account for all the parts. That is, having cutting pins, connection screws, etc. just rolling around in a drawer was just not an option.

Replacement parts: I was looking for an established tool-maker that had been around for a while so I could be sure that if anything broke or got lost I could actually get replacement parts easily. Again the cheapo, Ebay no-name straight from the counterfeit factory job would not be what I was after.

Extra features/ease of use: I took into account if the device had any neat features like being able to make washers or other shapes. The overall ease of use and setup was taken into consideration as well.

Armed with all those criteria, I went on the usual internet research trip. It quickly turned out that even with the above strict criteria there was a fair amount of choice out there. A lot of Italian made models, some German/Swiss, British etc.

More or less any country renowned for good craftsmanship would have a factory of sorts making quality jewelry tools.

The one that stood out was the Swanstrom cutter, US made.

Over and above ticking all the boxes, it comes with this system of pointy plastic inserts matching the cutting holes. The plastic pins are used to center the material in the cutter so washers can be cut. More on that later.

Swanstrom Disk Cutter 01

I like the compact size of the overall tool and the small footprint it has when all components are set in the heavy rubber storage base.

I think in theory the rubber storage base could be used as underlay when cutting disks, too, but I use a piece of the trusty “stair rubber” that I use in so many other instances where heavy hammering or vibration noise needs to be dampened.

There are a couple of key features to highlight with the Swanstrom: the tool is of a very high quality and finish, and there are no rough edges or poorly finished surfaces on any of the parts.

Swanstrom Disk Cutter 06 Swanstrom Disk Cutter 05

The large quick-tight handle on the center screw is really handy and the fact that someone thought of installing a spring-loaded handle that can be pushed down and turned out of the way is quite clever.

But by far the most attractive feature is the shape of the cutting face of the pins.

Swanstrom Disk Cutter 14

The Swanstrom cutting pins are ground on a slight angle which makes cutting through even fairly heavy gauge metal a breeze.

Most other disk cutters have flat-ground heads on the cutting pins which requires a lot more force to hammer through the material.

The use of the tool is very straightforward. First, take the cutter out of the storage unit.

Swanstrom Disk Cutter 09

Decide on the size of the disk you wish to cut. Open up the base of the tool to fit the sheet metal under the hole of choice. You can go incredibly close to the edge of the metal so the least amount of waste is created

Swanstrom Disk Cutter 12

Place a piece of metal of the same thickness as the one you are cutting between the base and the tom at the opposite side of the hole you are using to avoid the tool getting out of alignment when you tighten down the screw.

Swanstrom Disk Cutter 13

Tighten down the center screw, and if necessary push down the handle and turn it away from the side you are working on.

Swanstrom Disk Cutter 10

Take the cutting pin out that fits the hole and apply some lubricant onto the cutting edge. I use “Saw Glide” from Rio Grande but pretty much any type of lubrication will work. Even a humble piece of old candle will be suitable.

Swanstrom Disk Cutter cutting lube 01

Place the pin in the hole and make sure you have the tool set up on a shock absorbing surface. You can use pretty much any type of hammering device that is made from a softer material than the cutting pin. Some options are: brass mallet, wooden mallet, hard rubber hammer, nylon hammer, rawhide hammer… you get the gist. I just use my large rawhide hammer; it’s lead weighted and is more than adequately heavy and hard for the job.

Raw hide and nylon hammer

Mind you, it is not that great when doing the smaller disks, as the pin is thin enough to get stuck in the head of the hammer. I am still looking at getting a better setup but have so far been too stingy to get a brass mallet specifically for this. I don’t cut that many disks, after all. When I need a more resilient semi-soft faced hammer I use the nylon hammer.

Once all is lined up and tightened down, you hit the pin, preferably with one hard blow rather than many small soft blows. It takes a bit of practice to know how hard you need to hit to have the cutter go through but not so hard you cut holes in your bench.

Unless you plan on using the tool as a disposable unit (hardly attractive considering the $$ you have to spend), make sure you have a soft underlay, either a piece of stair rubber or a cutting board. That way the cutting pin doesn’t hit a hard surface when going through.

That is it: perfect disks every time, ready to be formed, drilled, sawed, enameled or whatever you plan to use them for.

A feature of the Swanstrom disk cutter is the ability to create perfect “washers” or doughnuts or whatever you want to call a circle with a hole in the center.

Setting up and creating the washers is a bit counterintuitive in that you actually start by creating the center hole in the preferred size.

You obviously do the setup in exactly the same fashion as described above.

The only thing to think of is making sure that you leave enough material around the hole to cover the size of the outside circle.

Once you have the center hole, you use the plastic cone plugs that you can get for the disk cutter (these are not included in the overall package but are a fairly cheap add-on that is worth getting if you ever plan on cutting circles with holes in the middle).

Swanstrom Disk Cutter 15 Swanstrom Disk Cutter 16

You take the piece of metal with the center hole and side it under the hole you plan to use as the outside diameter hole, then place the matching plastic cone plug with the pointy end down into the cutting hole. Because of the cone shape of the pointy end, it will automatically center the inside hole in the larger cutting hole.

Swanstrom Disk Cutter 18

With the hole centered, tighten down the center screw again with a shim of metal on the opposite side of the hole you are cutting in. Once tied down, lift out the plastic guide and do a quick visual to see if the hole is actually in the middle of the cutting hole. If so, follow the same procedure as for any other disk cut, i.e. lubricate the cutting pin, insert it, whack it and presto! You will have cut a perfect washer.

Swanstrom Disk Cutter 23

So all in all, I have been incredibly happy with the Swanstrom cutter; it’s good quality, solid, has great storage arrangement and cuts perfect disks every time. If you are into creating anything a little more exotic you can actually get “disk” cutters now in a bunch of other shapes like squares, rectangles, triangles and even hearts.

It’s a great tool to create both simple and more complex shapes without having to spend a lot of time sawing out the shapes.