On Mon, 10 Oct 2011 08:48:23 +0100, "N_Cook"
wrote:

I have one in front of me labelled
UTM 210-9 25435,3 watt probably Russian and can find no info
Like the standard pillar white/grey ceramic resistors but instead of the
wire returning down the flute of the ceramic there is a sprung join set in
the flute with bismuth solder or something. Anyone know a generic name for
this type of thermal cut out resistor or a maker name ?
Other than the opening temperature must be greater than the sustained power
rating temp of the resistor and lower than standard solder, anyone know what
sort of safety cut out temperature?


Used to be quite common in TV sets (fusible resistor).
Have a look at the top left diagram on page 4 of this which shows
mechanical drawing:-
http://www.vishay.com/docs/21008/kk.pdf

Geo