Bought from here
I have tried the magnet trick and it does not stick to either of the two wires of this TC. More so, screwing it inside an oven and turning the temperature up does produce some micro and then mili Volt reading on a DMM. However after turning the oven off the output voltage still rises for 1-2 minutes before it starts dropping.
Is this really a K-type thermocouple and if it is, is it a broken unit ?
I have bought another such K type TC. This one responds well to the magnet on one of its wires. There was a problem with the PCB, not the TC. Fixed it and the non-magnetic TC started working as well. It seems not all K type thermocouples will have their negative wire magnetized enough for a HDD magnet to pick it.