Help identifying a component

I've bought a load of components off bay - mostly 1000s of LEDs but also some other bits and pieces (300 micro switches, 1000 bridge rectifiers etc..). Not bad for 40 quid.

Amongst this lot is 250 'things' that I cannot identify. They are a 3pin component similar to a trice or a voltage regulator. The label on it has R3253 and X8425 on it. The heat sink has Italy stamped on it. They came in a bag with Gi46064 hand written on it.

Anyone got any ideas what they are ?

Hmm typing on iPad is dangerous. That's eBay and triac :o

It might be helpful if you posted clear pictures of the parts.

Here's a pic....

The diode test on your Multimeter, should give you an idea if its a bipolar transistor or not.

If it looks like 2 diodes back-to-back then itmay well be. If the common lead appears to be positive, then its a npn.

Assuming it is a npn power transistor - by no means certain - you can then put it on breadboard, make some guesses about which is the collector and emitter, put it a common emitter configuration with a base resistor and a load resistor and find its current gain, by measuring both currents.

You could then test it to destruction - or just getting very hot - by decreasing the load resistance and seeing what it will cope with.

Looks like a TI (Texas Instruments) logo, in case that helps narrow it down.

The part number may be meaningless. Sometimes manufacturers have standard parts made with custom part numbers on them. So-called "house numbered" parts aren't really meant for general consumption, and if you can't get a clue about the real part number the only way is to reverse engineer them.