I am building a magnetic switch but I need some ferrous parts and its proving to be impossible to fabricate or purchase anything suitable. I bought some 8mm square mild iron bar and tried to cut it to lengths of 10mm using a hack saw and file, but as shown in the picture the result is rubbish. The cut faces need to be square, true and flush. How can I fabricate something like this ? Or where could I get it made without it costing a fortune ? Or is there anything existing that I could buy, even if the dimensions are slightly different ? I need a quantity of 18.