As you know, all Stair Tools, Step Tools are not the same.  I have seen some made of wood, which will break, and metal/aluminum which will bend and loose it’s shape.  This can cause you to make errors in cutting and cost you money.  Some treads are as much as $70.00 each.  This could get very expensive or very ugly if the tool you use is defective.  This is why I designed the STEP DOCTOR, a tool that is used by professional carpenters and is simple enough for the average DIY’er.  The STEP DOCTOR is made of 1/4” ABS plastic, the same material used in cars.  It will not break or distort no matter how ruff you are on your tools.