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JAMS [was: International Ring Size Equivalents]


Dear Cutter,

I knew that we were behind the times, but did not have any idea
that it has been 130 years since we agreed to adopt metric. Now
that’s foot dragging!

Sorry to blame the Brits for all our woes. You are right, we
shortened the ton, changed the gallon and took the English ring
sizes and made them just as silly in our own way.

When I was in grade school, we were all told to learn metrics
because the country would be changing over in a few years.

It has been a few years and more. If Sweden can change the
direction of flow of traffic nationwide in a week, I think that
130 years is long enough for us to adopt the metric system. Any
craftsman who tries to divide an 11 5/16 inche tall cabinet by 7
drawers has a screw loose. It does not make life much easier to
use thousandths of an inch.

I am going to start a movement right here and now, beginning
with the bench jewelers on Orchid. I suggest will call the group
JAMS: Jewelers Adopt the Metric System.

Our slogan:

Anybody want to join?


Dear Alan, Count me in as an Aussie supporter for JAMS! Best
wishes, Rex Steele Merten


Dear Alan, We are all for your JAMS. Count us In. Doc and Liz


Or you could all migrate to Australia… preferably Western
Australia! Oz has been metric since (about) 1968… completely

Felicity in West Oz



Count me in! I’m not a bench jeweler (just a lapidary), but I
use metrics in my hobby and thousandths as well as fractions of
inches (and pounds) in my day job… I’m feeling very

Mark in Oregon


Alan, I’m sure if you designed a ring sizer/gauge and mandrel the
tool companies would be interested. Why bother trying to form a
group to do something that has obviously been collecting dust?
Just make up some prototypes and kick up the dust.The magazines
would love anything that could cause controversy. Just play up the
ease of use factor to the general public. It could be used as a
promo to get customers into the stores to find out their metric
ring sizes.Any new marketing ploy will win over the retailers.
Susan Sarantos @auag


Alan: I heartily agree with you! The time has long past to
remain on a system that is so difficult (compared to a decimal
one) to make calculations with. I was schooled in the metric
system throughout my professional education,with the result that
I am more comfortable using this, than the current one used in
the U.S…

However, having taken a course in machineshop practices, and
though there were charts on the walls to facilitate conversions
from from one system to the metric,this conversion step could be
avoided. Thus saving time and eliminating errors. But, I do think
the adoption of the metric system will be coming soon, it has
taken much to long ot overcome the resistance of a very
influential group, the auto- motive industry. However, the
demands of the European market and other overseas
marketplaces,most of whom use the metric system, have exerted
pressure to force such change. The biggest problem is obviously
the cost of retooling, and that is the primary reason for the
foot dragging. Please add my name to your list and perhaps the
renewed effort, we can at least, start the ball rolling.
Joe Dule


Hi Allan, I’ll join JAMS… I was brought up on metric… and
had to learn the British and American way as well. I have a set
of Digital calipers on my bench so that all i have to do is set
in Inches to meassure and then push the button to convert it to
metric… or vice versa.

Glad to join!
Dan Grandi


Hi Alan,

Include me in!

However there’s one way to become conversant in all three (bg)!
Spend some time each week working in a machine shop (.001").
Spend some time each week working as a carpenter for Habitat For
Humanity (fractions, 5/16"). Spend some time each week working on
jewelry ( mm).



Susan and Alan: Two weeks ago on e-bay auction I bid on a ring
sizer from widget supply in oregon. It is an aluminum stick that
goesto size 15…oh excuse me thats 24mm…oh no the other
side says united kingdom 75 or no. 35. It is made in india and
I got it on e-bay for $11.00. Can,t beat that. Ron from Idaho


As an Architect in practice for over 40 years I can attest to
the problems with dimensioning with the present system. When I
had to prepare plans for overseas it was painful to convert
overnight to a new" Metric" system,especially when you remember
that errors were invitations to extras & litigation.We dumb &
stubborn Americans are stuck using the English system. Maybe they
are still angry about losing the “Colonies.”

Stanley R.Rosenberg

... Just make up some prototypes and kick up the dust
[snip...] Any new marketing ploy will win over the retailers. 

Like what that gumshoe maker said: ‘Just do it’!

Count me in. I was brought up measuring with inches and stone
and feet and all that (til New Zealand went metric in 1967), and
now I use metrics everywhere. Even building work round the house
I’ve never looked back - imagine the ease of making a 5-drawer
cabinet or set of 5 shelves; divide the available height in mm by
5. Bingo. 50mm = 2" 100mm = 4" 200mm = 8" These are our general
standards now.

We use the british ring sizing system A to Z - Doh!
B r i a n A d a m R u t h B a i r d J e w e l l e r y ph/fx +64 9 817 6816 NEW ZEALAND


Hi: Somehow I lost myself in the shuffle - what is JAMS? - i,
too was brought up on metric, and had to adopt the English
measurement (inches, etc,) and occasionally conversion is


Joe Bokor


After I took a couple of classes at the Revere Academy I finally
started (at first I resisted immensely!) using the metric system -
boy did it make my life easier at the bench- however I also work
as video graphics designer so when I am doing that I have to
measure time in frames (30 frames a second). Sometimes when I am
at the store counting out change I get frames, the metric system,
regular time and money totally confused. I have too many different
numbers systems in my head!



Hi, I wish you tonnes of luck (sincerely) - there was quite a
movement in the engineering community in the States towards this
a few years ago - it never got too far. Even if something is
quite rational and has benefits it is often hard to get past the
emotional attachment. Given the amount of material already in
metric in the jewelry community the jump would not be a quantum
one. People probably have been using metric and not even
realizing it. You might encounter remarks like “Gee you mean a 10
X 8 stone is really 10 mm X 8 mm - wow - when did they change

I guess we are kilometers ahead of you in Canada ; )

Cameron Speedie
Island Gem and Rock


Hi Alan I am joining this club right now as a Canadian who have
learn with British system and changed to metric in the 70. The
metric is now integrated but when I have to buy metals in USA
even sometimes in Canada, I always have to look at all these
conversion tables to compare B&S gauges, inches, onces troy,
avoirdupoids, pennyweight dwt, grain, drams, fahrenheit (to name
only those ones) with the metric system. I know both sytems and
everything is so much easier with grams, millimeters and
centigrade. These three resume all of those different ways of
measure. The funny thing is that metric system takes about 1 day
to learn for the non intelligent ones. Have a good day Vincent Guy


Dear Alan, Just an aside, but there many European and Armenian
trained jewelers who use an even more esoteric measuring system,
Douzieme/Ligne. Oppi Untracht’s book Jewelry; Concepts and
includes it in his conversion tables. This system
was used by many French or Belgian or French Swiss goldsmiths as
well. At one time, this system was also used in European
gunsmithing. This system seems to survive only in the
measurements of watch movements; i.e. a "6 1/2 ligne movement"
for example.

When I first started working in a 60 year old Platinum shop, the
goldsmiths still expressed all of their dimensions in this
archaic way. A head for a ring, for example, was known to be 36
to 42 douzieme high, with the prongs being 19 to 25 douzieme
high from the upper base wire. Oddly enough, however, gemstone
dimensions were always expressed in millimeters. Talk about
being confused,The concept of B.and S. Gauge was even more
unknown to them! This system seems to have only one advantage
(that I can see), since its based on the division of a "ligne"
into twelfths (“douzieme”- in French) any measurement in
"ligne"so expressed can be divided in two, three, four (and by
further division, eight)or six very quickly . This allowed for
the marking out of pave and multiple settings to be accomplished
using only a “degree” type measuring device.

This Shop, however is now using metric and B&S gauge principally
and another bit of esoterica may soon become lost. Just a little
of my History, Eben


Eben, Thanks for your contribution to the confusion. You are
absolutely right about the inconsistency and difficulty of using
a variety of systems, including the douzieme system of
measurement. Confirming what you say, when I learned to make
jewelry in Germany, the commonly used name for a spring gauge
was a douzieme gauge, obviously a reference to the aniquated
French system of measurement.

I have always found it curious that many of the terms we use
today for setting and enameling, also come from French: Pave and
a jour or azure for setting and of course all those terms like
cloinsonee, grisaille, chempleve, plique a jour, basse taille,
etc. to describe enameling. (Note accents ommited). Most of these
do not even have English equivalents. Also, the Germans, Dutch
and many Americans refer to tubing as chenier, and burs as
fraisers, both coming from the French. And then there is
repoussee, and the list probably goes on. It is another testament
to the internationalism of jewelry and a vote for international
acceptance of the metric system.

Alan Revere
Revere Academy of Jewelry Arts
San Francisco


No, we’re sitting on the fence trying to decide if we want to
join Europe in full! The metric system is easier to use though. I
worked in America for a while and it was hell having to order
stuff in non-metric sizes, I had to sit there with a ruler
comparing all the dimensions.



I heard from a friend who had studied at the Revere Academy that
it is quite a good school for learning jewellery design and
crafting. But towards the end of course there are still many
things to learn yet the instructors are quite reluctant to teach,
is this true??

Thank you.

Tay Thye Sun