One of the things you want in a solder pick is low thermal
conductivity so that the pick will be less likely to draw heat away
from the joint. You can see from the values below that. Stainless
steel and Titanium are good choices from this point of view.
Tungsten is a little more then ten times better a conductor than the
stainless so much more likely to rob the solder and joint of heat.
Silver is the most thermally conductive metal and copper is a close
second. This is why large pieces of silver and copper are hard to
solder, the heat is drawn away so fast from the area the torch in
pointed. Thermal conductivity of some metals in W/(mK) at 300K
304 Stainless Steel 16
Carbon Steel 40
W (Tungsten) 173
A couple of other factors, are wetability, (the surface tension of
the pick with respect to molten solder) and melting point of course.
In my experience with the metals used for solder picks in the
presence of a good flux carbon steel is easiest to wet followed by
tungsten,stainless and then titanium being the hardest to wet.
W 3422C, 6192F
Ti 821668C, 3034F
Carbon Steel 1482C, 2700F
304 Stainless 1450C, 2650F
But melting point is only part of the story, hot strength is
probably more important. If you get titanium above 1650 F it gets
real soft softer than carbon steel at the same temperature. Stainless
maintains higher strength at the temperatures we are soldering most
of our work at and of course tungsten is hardly affected strength
wise at these low temperatures
So some things to think about when choosing a metal to use as a
James Binnion Metal Arts