If you don't have vise, or some clamps to hold your metal firmly, you will have a tough time with a hack saw. If you do it with a hacksaw you want as many Teeth per in (TPI) as you can find. You want to nick the edge with your blade, just as a slight guide to hold the blade on your line, but then you want to engage as many teeth in the metal as you can. Meaning a shallow angle. Again, I would just use a box knife, a ruler and square if it was available, if not just a knife and ruler. Mikek