Tools – cylindrical squares
The cylindrical square is a very useful tool. It also has the advantage in that it is easy to make and can be made on a simple lathe.
It is simply a length of round bar that has parallel sides and square ends. It has a hole through it so it can be bolted to the milling table.
fig cylindrical square
If one of these is bolted to the milling table it present a line at right angles to the milling table. If two of them are bolted to the milling table then a flat surface can be placed (ie bolted) to them and this surface will be at right angles to the milling surface. Because of this useful feature cylindrical squares often are made or are bought as matching pairs.