A2 Tool Steel: Heat Treatment and Grinding

• Machining, heat treatment and surface grinding of A2

• Dimensional change during heat treat

• Comparative measurement for accuracy up to 40 millionths of an inch

• Measuring parallelism as well as perpendicularity to a high degree of accuracy

I wanted to make my own set of 123 blocks which are used all the time in machining.  I started by making a smaller block and going through the whole process of heat treatment and grinding before buying all the stock I would need to make a full set.  I also ended up making a few punches out of the A2 tool steel as well.  I find tool steels to be very interesting materials to work with and this was the first project where I really learned about heat treating.  I also spent a good amount of time working on the surface grinder to grind my block into a tolerance of plus or minus 1 ten-thousandths of an inch.  I also got a chance to observe how relatively small changes in temperature can greatly impact the size of the part when measuring on such a small scale.  Overall, a good project to branch out into the world of precision grinding and measurement as well as starting to make some long lasting tools.