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Purchasing a ring size stretcher


I have recently become interested in purchasing a ring size
stretcher and reducer. It appears that this may be the best product
but was curious to find out if anyone had any actual experience with
this tool. I am having a difficult time wrapping my head around the
concept of reducing and stretching finished rings. I have not been
privy to seeing one of these devices at work nor have I had any
first hand experience with them. How many sizes on average can you
reduce and increase a ring from it’s original size and does the act
of sizing the ring on these devices cause scratches that need to be
cleaned up afterward? I plan to use this on a line of rings I am
having cast and so there will be the necessary clean-up from the
castings anyway but would love if anyone could shed some light on
these tools before I spend the $350.

Thank you!
Delias Thompson
Delias Studio, Inc.


Ring stretchers are basically only to be used on wedding bands that
are the same thickness and width all around. They stretch the band
uniformly, if there is a narrow to thick shank or a wide band with
cutouts it will stretch at the weakest point and break. They can be
used (very carefully and slight strecthing) with other rings but I
would not advise it without lots of practice on one.

Bill Wismar


They stretch by expanding the mandrel from inside with a tapered
ram. It leaves marks. They shrink by ramming the band into a conical
hole. Also leaves marks.

Be careful with castings. Sometimes they go fine sometimes not so
fine. 18K castings in particular have a tendency to just SNAP!

Stone set rings can be challenging. Any discontinuity in thickness
or density becomes a focal point for stress, leading to distortion or
breakage when stretching. Stone sets cannot be shrunk (well…I’ve
done it but they were etoile style bands and I really really held my

In shrinking, very wide bands tend to cup inside because the force
is generally applied at or near the outside edge of the band. If this
happens you can try to over shoot the size, then expand on the
mandrel but its an iffy thing. How much can you stretch? I’ve gotten
up to five sizes on really good bands cut from pipe. More often its
limited to one, two, MAYBE three sizes. Sometimes all you can go is a
smidge before the ring breaks.

You can increase your success rate by going easy. Try to muscle a
ring and it very well may pop. Finesse the thing along and you’ll get
more out of a ring. Stretch a quarter size, loupe the ring, if ok
stretch another quarter loupe it and so forth. You’re looking for
developing cracks or that funny orange peel look you sometimes get
just before the metal is at its limit.

Ok, that’s all the bad news. the good news is when the ring is
suitable it can save a bunch of time.

If you get one get a good one ($). Mine is over 40 years old.


Cynthia says (and she knows) that these only really work on solid
rings, they should NOT be used on any rings with stones or baskets,
as these areas are the weakest part of the ring (usually) and that
is where all of the metal movement is going to take place… NOT a
pretty site is you were ever to see it in action. The result is
called “remake the ring and, most often, buy new stones”.

John Dach


At a shop I worked at, we had a ring roller that was meant for
sizing up the shank of the ring and could have stones or design on
the front of the ring. It was like the Kagan Ring Roller. We also had
the stretcher, but as stated before, this only works well for bands.
I found that stretching did not leave a mark, if you were light with
the stretch and frequently moved the band. I would be concerned about
stretching rings with solder seams from fabricating or previous

More often with through with rings with stones to size up small
amounts, I opt for my mandrel and planishing hammer because I have
pretty good control with hammering up. Sometimes, it is just
necessary to either add or remove metal. This depends on the size of
the band and the size difference needs to be.

Hope this helps some.

Ring stretchers are basically only to be used on wedding bands
that are the same thickness and width all around. 

They are also quite good on woven/braided rings - again, same
thickness all around, no stones. Loren Damewood actually uses them
as an integral part of making his bands (at least he did in the
workshop I attended - which I highly recommend!).

Beth Wicker
Three Cats and a Dog Design Studio

Finesse the thing along and you'll get more out of a ring. 

Yes, yes and yes to all the posts today. Just the ability to shrink
a seamless wedding ring down without having to cut it and make it
"seamed", makes it worth having. It can also be used to stretch and
shrink “rings” -

bezels, bits and pieces of all kinds. Real handy device. We have two

  • one where the stretcher is worn out but the shrinker works great,
    and another style that stretches especially well. Both too old to
    recommend the brands to you - no longer in production…


Delias, I have one and I love it.

However, I’ve never “shrunk” a ring. I’ve never needed to, and I’m
not sure my rings would be the best candidate for this anyway.

I stretch them all the time. Some of my thinner rings I can stretch
a full size as long as they are annealed. Some of my heavier rings
are really hard to stretch. And I only go 1/4 size on them.

Are you having it shipped or are you picking up? It’s really heavy
so I’d pick it up if you can. Also, have them demonstrate. You’re not
supposed to just put in on there and stretch. You stretch a little,
rotate a little, stretch-rotate, stretch-rotate. Then fllip and
repeat. At least that’s how I was taught.

Sometimes I break rings and I learn that I can’t stretch that ring
that much or I was doing it too quickly. Different rings definitely
stretch differently. If it’s a band that goes wide/thin etc… your
weak points are going to be your thin areas, so stretch gently and
you’ll have to test it to see how far you can go.

I’d be interested to see what others do.


Amery, My experience with this stretcher is very similar to yours.
On a couple of occasions, when I’ve hesitated to do a job, I’ve had
jewelers tell me, “Oh, go ahead and stretch it…it will be alright”.
But each time, it was not alright and they had to make it good!! So,
Delias, go very carefully into that area. Don’t do rings with stones
in them or fancy basket work. Look at the sonstruction…if there
are many small connection points I would not take it on.

I have also shrunken a number of wedding bands over the years and
found it to work very well. Again, the ring must be annealed and one
must go slowly. I don’t use it much anymore as I am not doing that
kind of work at this time. Now and then but not often. Still, I will
never get rid of it!

Cheers from Don in SOFL.


Hello Amery, It sound as though you are making good use of your ring
stretcher. Several small times is better than one large stretch.
Check the ring size from both sides to make sure you are stretching
it evenly. Don’t try to do it all from one side. Also, if the ring
has engraving on the inside, wrap a bit of scotch tape around the
stretcher where the ring goes. This will protect the engraving. Have

Tom Arnold


When looking for a ring stretcher/reducer, which is a machine I can’t
live without, you should look for a stretcher with more splines
rather than less. The splines are what move apart when the handle is
pushed up, stretching the ring put on it. A 6 splined model is
usually better than a 4 spline model. Sometimes the edges of each
individual spline are a bit sharp on the edges, which will tend to
leave a series of small cut marks on the inside of the band being

If these marks are seen on the band after stretching, you will need
to do some handwork, lightly sanding/smoothing down those sharp edges
on the splines.

Takes a little work with say, a bit of 400 grit sandpaper, and maybe
a rubber abrasive wheel. When stretching up bands, I always have a
graduated ring mandrel at hand, and mark the position of the band on
the mandrel before I start stretching. I will only stretch a band
about 1/4 to 1/2 size before annealing ( stress relieving )and
stretching up again. Each time I will mark the ring’s new position on
the mandril before putting the ring on the stretcher, so I know how
much the ring is moving each time I stretch. If you don’t anneal
before stretching, you’ll likely blow out your solder seam, if there
is one.

Making ring bands smaller with the reducer wheel is much easier on
solder seams, and less annealing is required. The reducer will tend
to leave some small marks on the outside of a band being made
smaller, but I’ve found just wrapping a few layers of electrical tape
around the outside of the band can help eliminate these marks, if the
ring only gets reduced slightly. I have been experimenting with the
ring sizer, to see what can be done with it, as a forming tool, as
has Andy Cooperman. I plan to make a new instructional video soon
showing what a creative tool a ring stretcher/reducer can be.

Jay Whaley


Ring stretchers only really work well with solid or uniform rings,
as has been said. Beth is correct, I use them all the time when I’m
making rings, though I show people how to get most of the work done
without them, if necessary.

The lever-action bench model, which I’m guessing is the one that
started the discussion, and which includes the reducing press, works
much faster than the cheaper portable models I usually use in the
workshops, but has exactly the same principle, using a tapered shaft
to expand the diameter of the ring mandrel. I highly recommend
annealing a ring before attempting to size it up more than a half
size or so, but for just a small increase, it’s fine.

A friend told me that his jeweler insisted he buy a new wedding ring
because his plain platinum band was a quarter-size too small for
him, and the jeweler refused to attempt to change it. I handed him
one of my portables and showed him how to do it (a little at a time,
as has also been said previously) and within about five minutes he
was happily wearing his ring and trying to pay me for my services. He
asked me if I had any idea why the other guy wanted him to buy a new
ring… silly question. The guy probably needed to make a boat
payment or something. :slight_smile:


Still, I will never get rid of it! 

I don’t have one at the moment. But when I had access to one, and
only used it once a month it was priceless.

A lot of $$ for a tool which does only a very few things well, but
when it worked I tended to smile like an idiot. Much fun from a simple

Demand Designs
Analog/Digital Modelling & Goldsmithing


David Cruickshank.

I have found a ring sizer invaluable, mainly the compression system.
Stretching is really only of use for thinnish plain rings, maybe
twists and some other applications. Not with stones.

Whereas I now make most of my heavy broad rings a size or so larger
than reqd. and shrink them down to size after soldering. Giving me a
round ring. With little or no planishing needed.

I would buy the most powerful sizer with the greatest travel from
top to bottom. I often remove the V wheel and put, say, a doming block
or a swage block and have made very small press tools for bending or
punching where you need to have great control. Things too small for
the swing press.

Sometimes I put one thin ring on top of another then reverse them
when the sizes of the Vs are not quite suitable for my needs. Two
identical sizes. Or a shim of appropriate thickness can be placed
between the platten and the wheel to stop the platten closing
completely, as above.

Also useful for closing rings prior to soldering. First clean joint.
Re. Soldering a half round band.

Makes tension set rings a breeze! Compress, open with stretcher,
prepare setting and compress a bit, open ring carefully with reverse
action pliers (circlip) and insert stone.

I have very mixed feelings about tension set. Looks great but dont
guarantee it.

My phobia!

David. Australia

When looking for a ring stretcher/reducer, which is a machine I
can't live without, you should look for a stretcher with more splines
rather than less. The splines are what move apart when the handle
is pushed up, stretching the ring put on it. A 6 splined model is
usually better than a 4 spline model.

Yes, I agree. Our new ring Stretcher/reducer has 8 splines. This
will be on our website later this week and is available in US next

Matthew Durston
Durston Rolling Mills


I have two, one is a Kagan which has the mandrel mounted
horizontally, the other is a Vigor with the mandrel mounted
vertically. Although the Kagan is a better quality tool, I prefer to
use the Vigor most of the time, probably because I got used to using
a vertical model. The Vigor stretcher is at least twenty years old
and is used all the time, and is often treated like the shop’s
unwanted stepchild. The rolling mill gets oiled and covered, all the
forming tools too, but the poor old stretcher just gets used and

Like others, I use my stretcher / reducer all the time, couldn’t
live without it in fact. I use it for a lot more than just stretching
bands though, with a little ingenuity you will find it can be used as
a forming tool, a casting straightener-outer, a work hardening tool
(which sometimes morphs into a crack finder), a tool for assembling
two and three piece bands, as Beth suggested to tighten and
straighten woven bands and many other things. The one thing you don’t
want to use it for is stretching anything with a solder joint or a
fabricated setting, unless you wish to work on your re-fabrication
skills and torch control.

I use the reducer disc with a hydraulic press instead of with the
stretcher. Much more power and control and less marking. I polished
the inside of the holes and also use a small zip-lock bag laid on top
of the hole to protect the edges and sides of the band being reduced.
Works great and no gummy residue to remove. You end up with a whole
bunch of plastic circles laying all over the place though. As Jeff
says, it’s a surprisingly useful and fun tool that will leave you
smiling like an idiot, or crying because you were an idiot to try to
use it the way you tried to use it. Think before you stretch!

Dave Phelps

Purchasing a ring size stretcher 

The rings I am interested in stretching are fairly simple but I am
wholesaling them so I have been sizing quite a few lately. They are
simple in design and made from 10 gauge square wire stock. I had the
originals cast and I have been cutting and soldering them to size but
with as many orders as I am getting even this is becoming tedious. I
currently have them cast in a 8.5 and I could have the set cast in a
6 and stretch them up on my ring mandrel. Stretching them up on the
mandrel is incredibly easy because they are so soft when they come
back from the casting company. I have been able to stretch them two
full ring sizes without annealing. I am trying to decide if I should
have them cast again in the size 6 and that would take care of the
sizes between 6 and 8 and then I could use the 8.5 castings for
larger sizes beyond that. I do offer these rings with stones but I
can stretch the stock band and add the stone after stretching which
wouldn’t be a problem at all. I am always trying to save time on
repetitive tasks if at all possible. Thank you to all for your advice
and I have a friend who called yesterday and happens to
have the Kagan ring sizer I am considering. She is going to let me
come over and try it out. This will help a lot in my decision making.
I think it might be a good tool to have either way but in these tight
times I am trying to carefully consider costs before assuming any new

Delias Thompson
Delias Studio, Inc.


FYI, I was lucky enough to find my Kagan on eBay some years ago at a
very good price, maybe $80 or $100. You might get lucky too! I’ve
done very well on eBay over the years-- magnetic stirrer $10; Genie
lapidary unit $175, etc.

P.S. Merry Christmas and all Happy Holidays to All!