Make your own Mini engineers square from steel angle,
Using a hacksaw angle grinder or metal cut of saw you can make your own engineers square with just 3 cuts. Your cuts don't even have to be strait as the critical edge is the inside face of the angle
Step 1: Cutting..
Use a hacksaw, angle grinder or cut off saw to cut down one side of a piece of steel angle then cut the whole section off as show in the images.