Re: Which metal in bimetallic strip expands/contracts more when heated/cooled?

Hi Felicia,
In a bimetallic strip, any metals with different COEFFICIENTS OF EXPANSION 
can be fastened together to make a strip that bends with temperature. The 
metall that expands most with temperature also contracts most (as you 
would expect)

So Iron and brass are not the only metals that are used. A good choice of 
metals is copper/Invar. Invar is an exotic alloy of nickel that DOESN'T 
EXPAND or CONTRACT with temperature, over a wide range of temperatures, so 
INVAR makes a very good partner to something like brass for a bimetallic 
strip.

It is also important that the two metals are fairly strong, else when the 
more expansive metal expands, it can deform the softer metalalong its 
length and not actually bend it all !

Hope this helps.

Steve