How are rings sized?

This is the third of three posts that will focus on ring sizes. In this post I will go over the different methods used by jewelers to size a ring, and why some rings might be trickier than others to size.

The first post detailed factors you need to know to find your ring size, and the second post reviewed four sizers available on Amazon. 

Sizing Methods and Potential Issues


Now that you’ve found the size you need all that’s left is to get your ring sized by a reputable jeweler in your area. They’ll be able to walk you through their own processes and answer any concerns you may have. This post will aim to give you a general overview of how a ring is sized - up or down, explain a few of the issues that may arise with some methods, and overall issues that could prevent your ring from being sized at all.

The methods I’ll be detailing will include soldering, laser-welding, stretching, and compressing.


Soldering is my preferred method of sizing and, in my opinion, is the most effective, does the least “damage”, and is the longest lasting when done correctly. A soldered sizing job, done well, should yield a ring that looks indistinguishable from its original form, other than being bigger/smaller. Every effort should be made to exactly match the metal of the ring, eg – 14k yellow gold to 14k yellow gold. Not 10k or 18k yellow to the 14k yellow gold. The solder used should also match the metal of the ring.

Sizing Down

To decrease the size of a ring via soldering the ring band is marked with the exact measurement of metal required to be removed.

This excess metal is then cut out of the ring using a jeweler’s saw.

The band is manipulated closed, using pliers or a nylon or leather hammer, so that the cut ends are flush with each other. If the ends are not flush, a very thin saw blade will be used to cut through the seam again, which should ensure a clean, flush, joint. 

Once the jeweler is happy with the size and seam, the ring will be cleaned, dipped in a chemical solution to protect the metal if it’s gold or silver – platinum doesn’t need this step – and then soldered with the correct karat and color of solder.

Any excess solder is filed and sanded away, taking care not to remove material from the band.

Then the same finish is applied to it as the rest of the band, eg – high polish, satin, matt, engraved, etc. Pains should be taken to blend the finish into the original band to ensure a seamless look.

Sizing up

To increase the size of a ring via soldering the ring is cut using a jewelers saw and a piece of new, matching, metal is inserted. If the jeweler has a laser welder or an arc welder they may use that to “tack” the new metal in place.

As done when sizing down, the jeweler will ensure both seams between the band and the new metal are clean and flush, and then solder the new metal in place.

The excess material from the added metal is filed and sanded away to match the original shape of the band.

Once the new metal is perfectly blended into the band, the finish can be applied as described above.

Issues that may arise with soldering:

Heat and Set stones: There is always some form of risk when it comes to applying heat near set stones, some more than others, even if the jeweler takes every precaution, such as submerging the set portion in water, or wrapping it with soaking wet material/tissue paper. Sizing seams, in rings with set stones, should be as far from the stones as possible.

*No ring, or piece of jewelry, should ever be quenched (rapidly cooled in liquid) if it has set stones, regardless of the kind of gemstone.*
Diamonds have the least risk but can still be damaged. Small side diamonds may be affected by the heat, especially with regards to platinum rings, and can become cloudy or even burnt. Center stones with inclusions can fracture and possibly break.
Sapphires are also low risk, but higher than diamonds. If sapphire side stones are within a few millimeters of the seam to be soldered it may be advisable to use a different sizing method, such as laser welding.
Other colored gems like peridot, amethyst, and aquamarine should never have heat applied to them. A skilled jeweler will be able to “spot” solder a ring quickly enough that the heat will never reach the center stone.
Opals: I, personally, will avoid soldering a ring with opals in it. I will laser weld it instead. If your jeweler doesn’t have a laser welder, they may refuse to size your ring or recommend removing the opal before sizing and then resetting it afterwards, for an additional cost. 
Stones in Silver: Unlike gold or platinum which can be heated at exact points (spot soldered), silver needs to have the entire piece heated before solder will flow (melt). This means that any stones set in silver need to be removed before the piece is soldered, or the piece will need to be laser welded instead.
Previously sized: This is an issue that can affect a lot of the methods used for sizing. The are two main problems that can result from this.
The first will depend on the number of sizing seams, or namely on whether it was sized up or down previously. If it was sized down before, that is less of an issue as that means there should only be one sizing seam and the jeweler can use that by either cutting directly through the old seam or removing it entirely.
However, if the ring was sized up before then that means there are already two seams. The fix to this issue is to incorporate one of the seams if sizing down, or to remove the old sizing piece entirely, if sizing up, to make way for the new sizing piece. Depending on the jeweler, sizing up in this instance can cost extra due to the extra labor and the additional new metal the jeweler must use to cover the old sizing piece that is removed.
The second problem will depend on how many times the ring has being sized previously. All metal has a breaking point. Take a soda can pull-tab for example. At some point in our lives, I’m sure we have all flexed those back and forth until they broke. This is an example of metal fatigue, and it affects precious metals just as much as it does an aluminum pull-tab. If a ring has been sized up and down multiple times rippling or microfractures will be visible under magnification. Usually this is more of an issue with antique rings and if this is apparent in your ring then something called a half- or full-shank may be the best option for you. This is something I will cover in a future post.
A good jeweler will examine the ring under a microscope while you are in their store and inform you of all the above risks that apply.


Laser Welding

Laser welding is a great option for when soldering is too risky. Laser welding works by using a highly focused laser beam, that generates intense heat, to melt the metal. It can create temporary, breakable, joints – calling tacks or tacking, or more permanent, durable, joints such as with sizing. Laser wire is used as the “filler material” for these joints and is essentially hair-thin precious metal wire, which is available in every iteration of gold, platinum, and silver. This wire is what is melted onto the piece of jewelry by the laser.

The method of sizing with a Laser welder that I was taught follows the first few steps that soldering does, whether sizing up or down, but once the correct amount of metal has been removed or added the method changes. Instead, a deep “V” is cut into the ring, centered on the sizing seam, then wire, matching the rings metal, is built up to fill in the “V”. The jeweler needs to be methodical and care should be taken to ensure no gaps are left within the band. Once the “V” is filled, the excess material should be filed and sanded off until smooth.

Personally, after this step, I like to cut grooves that bisect the newly filled seam and extend slightly beyond the Vs edges. I then weld a unbroken strip of wire into these grooves to act as additional support, like a brace. After I will re-smooth the band and apply any finishes needed.

Now you might be wondering; if the laser is hot enough to melt metal, then how is that heat not a danger to any set stones? And the answer revolves around the lasers speed and precision. The speed at which the laser hits or, more accurately, the length of time that heat is applied is a fraction of a second and the area that a laser melts on each hit is smaller than the period at the end of this sentence. These two combined allow for jewelers to work even on platinum, which has a melting point of 3215°F/1768°F, while holding the piece in their bare hands! Honestly it’s kind of amazing, although hitting your fingers and nails with the laser is inevitable and the smell of burnt keratin is….interesting. Thankfully it doesn’t really hurt, especially for callused jeweler hands.

Issues with Laser welding

There are only two main issues I came across with laser welding.
The first is that it is more time-consuming than soldering and so can on occasionally be more expensive.
The second is that sometimes the welded material can be slightly brittle. This is because some of the alloys in platinum and gold can’t withstand the temperatures or they cool at different rates leading to microporosity. This can be mitigated if the jeweler takes their time, however sometimes it’s unavoidable. 
For rings sized via laser welding I would always recommend removing the ring before taking part in activities that are hard on your hands, like rock climbing, weightlifting, or gardening. That being said, that advise is good to follow for all rings, and will help prevent excess wear and tear or early metal fatigue.
Stretching and Compressing

These two are probably the easiest and fastest methods of sizing, and my least favorite. They are also the ones with the most restrictions.

A ring with set stones, most kinds of detailing, or that has been previously sized cannot be stretched or compressed. These methods will only work on unadorned, unsized, precious metal bands. Set stones would become loose or be crushed, detailing would be warped or squished, and sizing seams would break open or become “peaked”.


I’m starting with compressing because stretching has an alternative that doesn’t have the above restrictions.

The machine used for compression usually has the capability for both stretching and compressing.

The mechanism used to compress a ring consists of a thick, circular, base plate that has tapered depressions that graduate in size and another thick metal plate above the base plate that is moved with a long lever. Essentially, it’s a press or stamping style of equipment.

The ring to be compressed is placed into the tapered depressions until the jeweler finds the one it sits into with only 1 or 2mm protruding. The lever is pulled and the upper plate pushes the ring down into the tapered depression and is then released. The ring is removed and flipped over and replaced so the process can be repeated on the opposite side, making the ring symmetrical.

Issues with Compression

Sometimes the ring will develop a curved exterior, arcing from edge to edge, after being compressed. This can be filed flat, or left curved, and any tooling marks or scratches will be sanded away and then the ring can be finished. 

If the ring has any hidden internal weak points the ring can buckle at these areas and cause an uneven compression. The buckle points will also be more like to breakage in to future.


The stretching part of the equipment looks like a mandrel, that stands vertically, and technically it is. However, this mandrel is hollow and segmented. Another mandrel sits inside the hollow one and when the lever* is pulled this interior mandrel is pushed upwards and causes the segments to open. It’s similar to how a flower opens, albeit a dirty, upside-down, industrial flower.

The ring to be stretched is placed on the nested mandrels, held in place and, while exerting downward pressure on the ring, the jeweler will pull the lever in small and careful increments. It is very easy to overstretch a ring and so it must be removed from the mandrels and measured continuously throughout the process. The ring should also be flipped each time to ensure a symmetrical stretch. With a little experience, the jeweler can feel the ring stretch under their fingertips which helps to inform them when to release the lever.

*The same lever operates both the stretching and compressing mechanisms.

Issues with Stretching

Stretching can cause the ring to become noticeably thinner, especially if the ring is being increased by more than half a size. The thinning occurs unevenly which doesn’t look good, and can lead to an eventual breakage down the line. I wouldn’t recommend using stretching as a method for an increase of more than half a size.

Breakage at the time of stretching is also an issue. Sometimes a ring will have hidden weaknesses within the band. These weaknesses will withstand everyday wear but will break under excess stress. Such weak areas can be caused by impurities in the alloy, or porosity in the casting, etc.

The Stretching Alternative - Hammering

Hammering a ring up a size might seem more aggressive and damaging than stretching but the opposite is true. With this method the jeweler can be precise, controlled, and it only affects a small portion of the rings band. Hammering can also be done on rings with center and side stones, within reason.

To “hammer-up” a ring the ring must have a sizing gap which is an area devoid of stones and detailing. Sizing gaps are common on most rings. This sizing gap must be at least as thick as the rest of the ring, preferably a little thicker.

The ring is placed on the jeweler’s mandrel and, while exerting downward pressure, the jeweler uses a brass or steel hammer to make precise strikes to the sizing gap/base of the band. The strikes should hit the outer edge of the gap first and work to the center, and then be replicated on the other side. Like a pendulum starting from the highest point of its arc to the lowest point, then stopping it, and restarting from the opposite highest point back down to the lowest point. After one or two rounds of this, the ring is taken of the mandrel and flipped over and the process is repeated. Because the ring is on the mandrel, the jeweler can see exactly how much the size is increasing as they work. After reaching the desired size the hammer marks are cleaned up using a file and sandpaper, and the finish is reapplied. This method is best for small increases or a quarter to half size but can be used for up to three quarters or a full size depending on the ring.

Because the hammering is so precise not many issues arise from this method. Occasionally there might be a mis-strike but that usually ends up hitting the jewelers finger or thumb rather than the ring.



These are the most commonly used methods for sizing. Soldering is the most common and my favorite due it's speed and durability. Laser welding is fast becoming popular and more common but the cost of Laser Welders is prohibitive and so many smaller jewelers may not have them. Stretching and Compressing, while not my favorite, can be very useful in time sensitive situations but the ring should be thoroughly examined before hand.

Your local jeweler should be familiar with these methods and their pros and cons. After examining your ring under magnification, preferably a microscope but usually a loupe, they will be able to advise you of the best method for your piece.


My next post will be in two weeks, on January 30th. I'm torn between a couple of options for the topics so I will be placing a poll on my Instagram in the next few days. 

If you have any topics you would like me to cover you can message me on my IG @orin_designs or email me at

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