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A 1-2-3 block is a piece of machined metal that is precisely one inch by two inches by three inches, and those dimensions can be relied on. They are used for work holding and positioning.
They are often made of a very strong steel. I this case I made of 4140 steel.
I machined the top of the block using a roughing end mill, after machining the entire surface flat I switched to a fly-cutter and made very slow passes to produce a very smooth surface.
I squared the two pieces of steel that I had using the "CNC" method
Once I had machined all of the sides with the endmill I finished them with fly-cutter to produce as smooth a finish as possible.
I colored the part blue and used the granite stone to map out all of my features.
Finding the edge to begin on the features.
I selected a pilot bit that was similar in size to the larger bit's web
Spotting the holes to be drilled.
WARNING!
Wear your safety glasses!
When drilling through an interrupted cut be sure to evacuate your chips and lubricate often! Otherwise you will break the bit like I did and likely produce a projectile.
This chunk of drill bit landed about 30 feet from the workpiece.
There is a lot of power in these machines.
Next came the features to my block.
I had to mount the part into the vice at exactly 45 degrees and take slow passes until I reached my target feature dimension.
Now that the features are complete, it is time for heat treatment.
Heat treatment is a process by which metal is heated to a specific temperature then cooled in a controlled way, sometimes with a reheating process involved.
For more information on Heat treatment CLICK HERE
For the heat treatment of this 4140 steel, I needed to heat the part to just over 1,500 and let it sit at that temperature for an hour and a half. I placed the parts in while the oven was cold.
While I waited for the heat treatment process I added some finishing touches to a hammer project I had been working on the side.
After an hour and half at 1550 degrees F, it was time to remove the 1-2-3 blocks from the oven. I Quenched them in Automatic Transmission Fluid
The finished heat-treated 1-2-3 blocks.
Next came surface grinding.
Surface grinding removes a very small and accurate amount of material from the surface of a part.
While I was grinding the short end of the block the stone grabbed a hold of the part and pulled t into itself. This caused the stone to break and throw the part violently and made a tremendous bang. I'm not sure what caused the piece to get loose and be sucked up into the wheel, but I think it may have been operator error.
These machines are dangerous and should be treated with diligence and respect
With the help of Evan we got a new wheel installed and soon the project was complete.
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