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How to measure the size of a ring


#1

Hi everybody,

I need a little help understanding the correct way to measure the
size of a ring. Especially wide rings.

I have a ring stick. Do I just slide the ring onto the stick and
take the measurement from the edge of the ring that is on the wider
end of the stick? Or should I try to estimate where the middle part
of a wide ring falls on the ring stick?

Also… I have two ring sticks. The first one I bought a few years
ago was the cheap black plastic kind. Recently I saw one advertized
on eBay that is an aluminum one. I thought this would really impress
my customers. It is a beautiful thing to hold and look at with US
sizes in red and European sizes in black. My concern though is that
the dang thing is only 10 inches long including the handle. Is that
too small to accurately measure a ring?

Sorry if this sounds like a basic question. I’ve searched the
Ganoksin archives and can’t find anything. Any help would be
appreciated.

Dan T.


#2

Dan, A steel mandrel is the most durable and accurate. They come
solid and slotted. The slotted is needed if you are measuring a ring
that has a protruding culet to avoid accidently chipping the stone.
These will last a lifetime whereas aluminum and plastic wear and dent
easily. The same goes for the ring sizers…The metal ones again are
the most accurate. I think they are nickel silver and chrome
finished. Mark


#3

Hello Dan:

The size is not an estimate of the middle. The size is the edge on
the wider end of the stick. Always be careful to look inside the ring
and make sure the culet of any stones are not in the way before
sliding the ring on the stick or you might break the stone. Just
sliding a ring down on a stick doesn’t mean that is the size either,
many rings are oval or bent from wear and may need to be rounded up
to get an accurate size. Be careful when rounding out rings. Stones
will sometimes become loose or even fall out. Thin weak shanks can
crack or break. Solder joints can pop open. If you use a raw hide
mallet to tap the shank round be sure the inside isn’t hollowd out or
you’ll wind up with ugly dents on the sides. I don’t think that the
10" ring stick is too short.

Michael R. Mathews Sr. Victoria,Texas USA


#4

Dear Dan T

There are many cheap imported Ring sticks that come from all over
the world. Each of them has its use. But the best thing is to buy a
Heat Treated US made Steel Ring Mandrel with sizes stamped & look
for one that is stepped.

  1. The Aluminum Ring stick that you mentioned with US/Euro sizes is
    made with a Peal & stick on scale that is hand pasted on a tapered
    aluminum rod. It has no accuracy what so ever. This is made for a
    store / reseller to check for a size made by a manufacturer.

  2. The Black Plastic Ring Stick is also an estimator for a reseller
    but it is more accurate than the aluminum one The numbers and sizing
    is in the molding die and does not vary from one to other provided
    they are made by the same manufacturer. Beware that these come from
    several countries and they are not necessarily the same.

As far as method of Measuring the Ring. Pull the Ring on to the
Steel mandrel as far as you can go with a decent force so as to
reshape the ring as it may have been bent on the edges. You have to
estimate where the middle part of the wide ring is and that is the
size you go by.

Kenneth Singh
karat46@aol.com
46 Jewelry Supply


#5
I need a little help understanding the correct way to measure the
size of a ring. Especially wide rings. 

The main thing to understand is the size of the ring is a function
of it’s inside diameter at it’s smallest point. I say that since
many rings have a “comfort fit” convex inside, or a beveled inside
edge. So when you measure a ring with a mandrel or 'ring stick",
what you have to do is read the size where that minimum inside
diameter is contacting the stick. If the ring is a good cylinder
inside, not tapered or “comfort fit”, then the measurement will be
at the leading edge of the ring, where that edge jams tight on the
stick. If the ring is “comfort fit”, then the actual contact area
will be close to the center line of the ring, not it’s edge. So how
you read the size of a given ring depends on it’s inside shape.

Now, how you determine what size a ring should be differs from just
sizing the ring, and depends on how closely the sizing bands you’ve
used match the width of the ring to be fitted. Wider bands tend to
feel tighter than narrower ones of the same size, so if you size a
finger with narrow sizers, then a wide band made for that finger
will need to be a little larger in size in order to fit the same.
How much larger depends on the person, but an 1/8 to a 1/4 size is
common.

   My concern though is that the dang thing is only 10 inches long
including the handle. Is that too small to accurately measure a
ring? 

The shorter length just means it tapers more quickly. What’s
important is that the sizes be accurately marked, not the degree of
taper. Some of the cheap ring sticks are not very accurately
marked… Remember what I say above. The size is where the minimum
inside diameter of the ring contacts the stick. Now, a comfort fit
or tapered band, if it tapers more slowly than the mandrel or ring
stick used, will be harder to measure, since then you have to sort
of guess. But you can come close.

Frankly, if you wish accurate sizes, for my money, I’d skip those
light weight sticks all together, and just get a good, accurate,
steel mandrel. That’s the actual tool used to size the rings for
real, when adjusting the size, rounding them out with a mallet, or
whatever. Unless all you’re doing is front counter ring sizing, the
sticks aren’t as useful. They’re merely a lighter and cheaper
substitute for the most part (with perhaps, the exception of ones
like what I think you describe, which may have several scales on it,
which can be convenient when converting, especially from the
european metric ring sizes to the U.S. ones) In buying mandrels, I
prefer the american made ones from the jarvi company. Good accurate
markings, properly tempered steel, and well finished.

Also, in sizing stone set rings, remember to always check whether
culets of stones project through the ring. If so, use a grooved
mandrel so the culets aren’t jammed against the mandrel (they’ll
chip. even diamonds…). even the softer plastic ring sticks can
force a stone loose in it’s mounting if it’s culet is jammed against
it.

peter


#6

I seem to differ from some on how to measure a ring size. I always
measure at the center of the shank or band. In all of my years of
building rings, I have never built a ring that didn’t have a somewhat
or more tapered inside. It has always come out somewhat saddle shaped
on the inside due to rounding and stretching. Furthermore, the edges
are closest to the joints and for comfort, should have a little
relief. Thus, the only reliable part of the ring that I have found is
the center.

Accounting for out of roundness is a must. If you don’t know what
you are doing, don’t round it up. I have seen broken stones, broken
enamel, broken school rings… should I go on?

Bruce D. Holmgrain
JA Certified Master Bench Jeweler
http://www.goldwerx.com


#7
    As far as method of Measuring the Ring. Pull the Ring on to
the Steel mandrel as far as you can go with a decent force so as to
reshape the ring as it may have been bent on the edges. 

PLEASE don’t forget to check that a stone pavilion does not protrude
into the finger hole. I’ve had to recut a number of stones because
the jeweler didn’t check first!

Jeffrey Everett


#8

Peter gives an excellent overview of the challenge of sizing. This
is truly an art. Some additional thoughts: All mandrels and sizers
are not created equal. That is, mandrels–steel, plastic, hollow
foam, whatever-- may vary significantly. Ditto ring sizers. I’ve
seen them fluctuate by up to 1/2 size and routinely find them out of
sync by 1/4 size. (This is not including the difference between a
wide band and thin band ring sizer, which is supposed to vary.) One
would think that there is an atomic ring sizer in some lab in
Switzerland which has the official size 6, 7 or 81/4 or whatever
(like the atomic clock) but, even if this were to exist, it would be
moot.

The most important thing is to make sure that your sizers match your
mandrel and that your mandrel matches the mandrel at the store or
gallery that you are working with (if you are working with a store or
gallery). Additionally it is important that you measure the ring in
a consistent manner. It really doesn’t matter if you are measuring
from the leading edge, the middle or even the back edge of the ring
as long as you do so consistently (and in concert with the gallery or
store). Changing measuring points can skew a size by as much as 3/4
size on a wide ring.

If I do a lot of work with a gallery, I’ll find a mandrel that
matches mine and mail it to them. When we work on a ring together,
they can slide their ring sizer onto my mandrel and let me know the
size–on my mandrel. If they don’t have a matching mandrel, then
they can take one of my rings (in stock) measure it and send me that
ring and their measurement so that I have a baseline to work off of.
(Such as their mandrel measures 1/8 size larger then mine, so that if
they request an 8 I’ll make it an 8 1/8.)

This a pretty complex issue that is very basic but intrinsically
important. Remember: Make sure to compare apples to apples and
oranges to oranges.

Take care, Andy Cooperman


#9
Frankly, if you wish accurate sizes, for my money, I'd skip those
light weight sticks all together, and just get a good, accurate,
steel mandrel.  That's the actual tool used to size the rings for
real, when adjusting the size, rounding them out with a mallet, or
whatever.

Peter’s right on here on the recommendation for the steel mandrel…
Costs a bit more than the sticks, and the first time you use it as a
tool (to undeform a ring, and how do folks do stuff like that to
their jewelry?) it pays for itself…

Keep mine with a thin coat of vaseline on it, wipe off before use,
because they will rust… The grooved is probably best if you’re only
going to have one, and they come smooth taper, stepped, also
ungrooved and even D-shaped (for like with big cabbed rings)… To get
an idea of the types, check out a Rio catalog (among others)… –
Gary W. Bourbonais


#10

Arrrgh!!! The measuring of ring/finger sizes is the bane of my
existence. Peter gave a good foundation of how to measure. I am of
the opinion that you must measure to the leading edge when using a
ring mandrel. Measuring to the middle of the band is just fine as
long as you are the only one involved. However if there are others
like your gallery or retail stores they are probably, no make that
definitely using a different mandrel from the one you are using and
will probably mess up the measurement due to differences in taper
angle and the incredible variation in sizes each mandrel indicates
if they have to guess the measurement at the middle.

The second part to my rant is that there is no I repeat NO

consistency in indicated ring sizes from mandrel to mandrel or
finger gauge to finger gauge. I bought a dozen mandrels last summer
trying to find a “standard” to use. Not only do they vary from one
manufacturer to another the damn things vary from the same
manufacturer! And it is not something easy like mandrel “A” is 1/8
size smaller than mandrel “B” on they vary depending on what size
you are measuring. If you want a good laugh try comparing the sizes
on mandrels that you have access to.

We now have a "Standard" mandrel, all rings are checked on it

before shipping. All finger gauges are checked against it and
resized and re marked to conform to the standard. We have dozens of
sets of finger gages in several widths When we get a mail or
internet order we send a group of gages (3-5 gages that bracket the
customers stated size) to each customer to allow them to verify the
proper size. They have all been checked against the “Standard” for
proper size. We go through all of this because I got tired of having
to remake rings when someone screwed up the sizing check. We still
have the occasional problem but it is not as bad as it used to be.

I have heard that Steve Kretchmer sends each of his stores a

machined set of finger gages and mandrel. I have thought about this
but I have not yet found a supplier of the gages and mandrels that
produces a truly precision product in US sizes.

Jim Binnion James Binnion Metal Arts Phone (360) 756-6550 Toll Free
(877) 408 7287 Fax (360) 756-2160 http://www.mokume-gane.com
@James_Binnion Member of the Better Business Bureau


#11

Attn. Jim Ring mandrels will always vary in sizes even if they are
made by the same manufacturer on an expensive CNC Lathe with
machining and holding accuracy to 3 thousands of an inch. You need
to weed out the less accurate ones and indicate the better ones.

This exactly how we make our Mandrels today. Yes, I own and operate
a Mandrel manufacturing facility that has been supplying mandrels to
Dixon and Gesswien for more than 30 years in this business.

If you are looking for the best and accurate mandrels then I know
for a fact that the GESSWEIN 16 & the GESSWEIN 17 are the ultimate
in mass produced mandrels. Speaking in averages we get one out of
15pcs that qualifies for this standard. It is not only the accuracy
in size but also the Hardening process that makes these Mandrels
highly desirable. Each mandrel is hardened in a Salt Bath and
checked for accuracy for all sizes.

You will not be able to buy a highly accurate and well heat treated
steel mandrel for $14.00 or $15.00. Not with US labor rates at
atleast $10.00 an hour for a simple machine operator.

Start with 2 lb. of Good Material, Accurate Taper cutting, Line
Grooves, Numbering, Polishing, heat treating and Re-polishing,
Verifying the Sizes after Final Polishing applying Rust Preventive
Packaging & Freight.

We do get custom orders from suppliers to Mass merchandisers such as
Service Merchandise, Town and Country, Walmart, etc., and they order
a batch of 100 or 50 exactly matched mandrels so that the counter
sales person and the repair centers are using the same sizing.

It is in the polishing process that the major changes in sizing
occurs. A difference is 16 thousands of an inch is a difference in
1/2 a ring size.

Kenneth singh
karat46@aol.com


#12
    Arrrgh!!! The measuring of ring/finger sizes is the bane of my
existence. Peter gave a good foundation of how to measure. I am of
the opinion that you must measure to the leading edge when using a
ring mandrel.  Measuring to the middle of the  band is just fine
as long as you are the only one involved. 

I feel compelled to speak up here. Having sized most probably well
over 10,000 rings, I’ve noticed that wide rings fit tighter and must
be sized larger. If you take a 2 mm band and a 10 mm band at size 6
at the leading edge, the 10 mm band will be too tight on most if not
all people. Therefore, I always use the middle of the ring, and it
always works, meaning, I’ve never had a return because of mis-sizing.
When I used to use the leading edge, I had constant returns of wide
bands to make them larger. Comfort fit band would be the only
exception. Almost every ring I make now is of the “finger shape”, a
rounded oblong square, or slightly smaller at the top. This shape is
more comfortable, fits the finger better because it’s the same shape
as the finger, and resists ring twist.

Jeffrey Everett


#13

Measure the finger with the appropriate narrow or wide sizers. Use
the centre of the ring on the mandrel to determine its size.

A very simple approach which makes sense and resulted in the fewest
re-sizes.

Jeff


#14

Kenneth, Thanks for your input. I will order one to review. If they
are being hand polished then I can see where you will have tolerance
problems. I am wondering why the high quality mandrels are not
ground to final size? You should be able to hold .001 tolerance
along a 10" length with a standard CNC grinding center. And the
grinding can be done after the hardening so that the distortion in
hardening can be removed. I don’t expect to pay 10-15 Dollars for a
mandrel that is of good quality but if I pay two to three times that
amount then I expect it to be accurate. And so far in my experience
cost does not seem to be a good indicator of quality.

Jim Binnion James Binnion Metal Arts Phone (360) 756-6550 Toll Free
(877) 408 7287 Fax (360) 756-2160 http://www.mokume-gane.com
@James_Binnion Member of the Better Business Bureau


#15

Jeffery, While I have not done 10,000 rings I have done a sizeable
fraction of that number. I am keenly aware of the effect of width on
the fit of a ring and I do apply a correction to the measured size.
I also correct for comfort fits. If I am the one who measured the
client I don’t ever have any problem with miss sized rings either.
Where the problem comes in is when other people get involved and
apply their own corrections like measuring to the middle. Or as
Kenneth has just pointed out only one in fifteen mandrels is
accurate so what is the likelihood of their mandrel and mine being
in sync? And lets not even talk about the accuracy of finger gages.
It is a problem because there is no standard that is adhered to by
everyone and the required accuracy is fairly tight. Again as Kenneth
points out 1/2 size is .016" . This is the equivalent of 8 sheets of
notebook paper, not very much. And we get stores and clients trying
to order rings to a tolerance of 1/8 size that is .004"

Jim Binnion James Binnion Metal Arts Phone (360) 756-6550 Toll Free
(877) 408 7287 Fax (360) 756-2160 http://www.mokume-gane.com
@James_Binnion Member of the Better Business Bureau


#16
       If you are looking for the best and accurate mandrels then
I know for a fact that the GESSWEIN 16 & the GESSWEIN 17 are the
ultimate in mass produced mandrels. 

Kenneth, What’s your opinion of the Jarvi mandrels?

Peter Rowe


#17

Attn Peter Gesswein 16 & 17 are better because of special heat
treating and each size on the mandrel is checked individually.

Jarvi makes excellent products. Jarvi and Herlot are the olny two US
manufacurers of Mandrels. I bought Herlot 10 years ago. We did not
have a price increase for the past 15 years.

We have to deal with cheaper imports. The cost of a Beautiful Steel
Mandrel with Hard Chrome from India is $2.50. The tool dealers are
bothered with prices not quality.

For Mandrel Buyers out there. Hardness is as important as Accuracy.
Because a bumpy mandrel is not going to be accurate for long.

Best way to check for a good mandrel is to run a file over it and
see if it glides or if the file digs in. If it is not hardened it is
not good even if it is accurate. Next take a ball pein hammer and
lightly tap anywhere on the mandrel look for marks. Mandrels are
just case hardened so they will leave a bump but a soft one will
show up very fast.

Quickest way to check if the taper is good for sizing is measure
size 2 & size 13 with your best finger gauge.

Finger Sizers It is best to measure every size of your finger
guage. These may put together by some kids sitting on the factory
floor in ill light Indian sweat shops.

My freind Mr Liberati from Rhode Island made the best Finger sizers.
He gave up due to health and cheaper imports.

Regards
Kenneth Singh
karat46@aol.com


#18

I do not have major experience sizing rings but while making a ring
and determining band length etc. I always check the inside diameter
with my electronic calipers. It occurred to me, while reading this
thread, that whatever gauge for measuring a ring is used it is really
the inside diameter measurement that matters.

I realize that jewelry stores etc. would probably be slow to adopt
the use of calipers but it would certainly cut through the confusion

Jim, not such terrible trouble to be having, it means you must be
making many rings!

Cheers,
Donna Hiebert