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<font size=3>Robin,<br><br>
Any metric wired piano will have slightly different sized wire than an
American gauge wired piano. There are some sizes which match very
closely, and others which do not. Here is a comparison
table:<br><br>
</font><font size=2>_____________________________________<br>
American
Wire
<x-tab> </x-tab> Metric
wire <br>
Gage
.001" mm
<x-tab> </x-tab>
.001" mm<br><br>
12 <x-tab> </x-tab>.029" .737mm
<x-tab> </x-tab>.0285"
.725mm <br>
12.5 <x-tab> </x-tab>.030" .762
<x-tab> </x-tab>.0295 .750
<br>
13 <x-tab> </x-tab>.031" .787
<x-tab> </x-tab>.0305 .775
<br>
13.5 <x-tab> </x-tab>.032"
.813<x-tab> </x-tab>.0315
.800 <br>
14 <x-tab> </x-tab>.033" .838
<x-tab> </x-tab>.0325 .825 <br>
14.5 <x-tab> </x-tab>.034"
.864<x-tab> </x-tab>.0335
.850 <br>
15 <x-tab> </x-tab>.035" .889
<x-tab> </x-tab>.0344 .875
<br>
15.5 <x-tab> </x-tab>.036" .914
<x-tab> </x-tab>.0354 .900
<br>
16 <x-tab> </x-tab>.037"
.940<x-tab> </x-tab>.0364
.925 <br>
16.5 <x-tab> </x-tab>.038"
.965<x-tab> </x-tab>.0374
.950 <br>
17 <x-tab> </x-tab>.039"
.991<x-tab> </x-tab>.0384
.975 <br>
17.5 <x-tab> </x-tab>.040"
1.016<x-tab> </x-tab>.0394 1.000
<br>
18 <x-tab> </x-tab>.041"
1.041<x-tab> </x-tab>.0404 1.025
<br>
18.5 <x-tab> </x-tab>.042"
1.063<x-tab> </x-tab>.0413 1.050
<br>
19 <x-tab> </x-tab>.043"
1.092<x-tab> </x-tab>.0423 1.075
<br>
19.5 <x-tab> </x-tab>.044"
1.118<x-tab> </x-tab>.0433 1.100
<br>
20 <x-tab> </x-tab>.045"
1.143<x-tab> </x-tab>.0443 1.125
<br>
20.5 <x-tab> </x-tab>.046"
<x-tab> </x-tab><x-tab> </x-tab>.0453
1.150
<br>
21 <x-tab> </x-tab>.047" 1.194
<x-tab> </x-tab>.0463 1.175 <br>
21.5 <x-tab> </x-tab>.048"
<x-tab> </x-tab><x-tab> </x-tab>.0472
1.200
<br>
22 <x-tab> </x-tab>.049" 1.245
<x-tab> </x-tab>.0482 1.225 <br>
23 <x-tab> </x-tab>.050"
1.295<x-tab> </x-tab>.0512 1.300
<br>
23.5
<x-tab> </x-tab><x-tab> </x-tab>.0531
1.350 <br>
24 <x-tab> </x-tab>.053" 1.346
<x-tab> </x-tab>.0551 1.400 <br>
24.5
<x-tab> </x-tab><x-tab> </x-tab>.0571
1.450
<br>
25 <x-tab> </x-tab>.055" 1.397
<x-tab> </x-tab>.0591 1.500 <br>
26
<x-tab> </x-tab><x-tab> </x-tab>.0630
1.600
<br><br>
</font><font size=3>As you can see, metric wire sizes step in .025mm
increments while English sizes step in .001" increments. This
causes the metric wires to be slightly different, and usually smaller,
than English sizes. Once you reach #16 they are very close to the
same, then at #23 the metric wire becomes larger than the English
size. This is the reason for being careful what you replace the
wire with. Measuring the wire is good advice.<br><br>
Most Roslau wire sold in the US has been re-packaged to match the closest
English size. If you buy it in Germany it will be the metric sizes
as listed above. Same with Suzuki wire from Japan.<br><br>
Don't worry about wire sizes leading to string breakage - this is not the
case. If you go smaller, the string tension for a given pitch goes
down proportionally along with the string strength. This means that
the percentage of tensile strength will be almost exactly the same on a
given note if you replace the wire with a size larger or smaller than was
intended. You can screw up the tuning and tone pretty well, but the
string will not be any more or less likely to break if the wire is
wrong.<br><br>
There have been lots of threads on string breakage here, so you can check
the archives. The bottom line is almost always heavy use combined
with worn hammers. Replace all the affected wire, shape the hammers and
keep them shaped, and the string breakage will be reduced to a
minimum.<br><br>
Don Mannino RPT<br>
Kawai America<br>
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