Metric system

Jewelry Discussion
41 
    once you get under half a mm, no one stays with metric

I do . Here in New Zealand I was brought up with one way and changed
to metric. I find it’s easy to operate in meters for building my
studio (plus or minus one or two mm) to refining an accurate master
(tolerance of .01). If I wanted more detail I’d have a better
measuring gauge and work to a tolerance of 0.001mm.

My biggest complaint about measurement systems is to do with
teaching jewellery (sorry, jewelry) classes in USA. Wire ga. I don’t
understand the use of ga. How, for example, can you calculate and
measure half a ga? Let alone calculate and measure and produce a
piece of wire with, say, 10% clearance in a hole. For these classes I
usually have to arm myself with mm/ga equivalents and hope I don’t
have to work with that system.

Then when I was teaching in Canada I had to order some silver stock
in both systems: 18" of something-ga wire, 1.2mm plate 6" square… I
was realling. Or is that reeling.

Mind you, I heard a good explanation of farenheit over celcius once:
0degF - pretty cold for humans but not deadly 100degF - hot for
humans but not exactly deadly.

Brian

B r i a n A d a m
e y e g l a s s e s j e w e l l e r y
518 South Titirangi Road
Auckland NEW ZEALAND
ph +64 9 817 6816
www.adam.co.nz

42

Another reason why the U.S. should go metric: To minimize conversion
errors.

“Great Wire Jewelry” (by Irene From Petersen) was translated into
English from the original Danish. In each project, wire is described
by both gauge and thickness in millimeters:

26-gauge (0.5 mm)
24-gauge (0.6 mm)	
22-gauge (0.8 mm)	
20-gauge 	(1.0 mm)	
18-gauge (1.2 mm)	
16-gauge (1.5 mm)	
14-gauge (2.0 mm)

I think those numbers are wrong–mismatched, actually–and should
be:

26-gauge (0.4 mm)
24-gauge (0.5 mm)
22-gauge (0.6 mm)
20-gauge (0.8 mm)
18-gauge (1.0 mm)
16-gauge (1.2 mm)
14-gauge (1.5 mm)
12-gauge (2.0 mm)

However, this would mean that the book is full of significant
errors, which is unlikely. I, on the other hand, am “numerically
challenged” and make math errors all the time. I would appreciate
help understanding these numbers! Thanks–Janet

43

Janet,

Unfortunately there are many "Wire Gages" There is American Wire

(Brown & Sharpe) Gage, US Steel Wire Gage, British Standard
(Imperial) Wire Gage , Music (Piano) Wire Gage , Birmingham (Stub’s
Iron) Wire Gage , Stub’s Steel Wire Gage . Each one is sightly
different. There is a web site that has a calculator for converting
between them at
efunda: wire gage Size Calculator (you
can use it free for a short time then they ask you to pay)

It looks like the translator was using the British Standard
(Imperial) Wire Gage and you were using the American Wire (Brown &
Sharpe) gage.

Jim Binnion

James Binnion Metal Arts
Phone (360) 756-6550
Toll Free (877) 408 7287
Fax (360) 756-2160

@James_Binnion
Member of the Better Business Bureau

44

Here is a conversion chart from wire gauge numbers to metric and
English decimal measurements:

http://www.reade.com/Conversion/wire_gauge.html

generally ignore the S.W.G. ( standard wire gauge) column you want
the AWG and BSG column

jesse