Trouble with HSS tool being destroyed by mild steel

[Dan Boy]

I have a custom made HSS tool from a piece of regular 10mm2. I have been careful to make sure the tool height is correct. It is a radius tool so there is not a sharp point to it yet when it comes into contact with the steel, the steel eats it away like it is made of plastic.

I'm sure I am doing something very basic here but I just can't see what is wrong.

Does anyone have any suggestions?

Thanks, Dan.