Jigsaw and a file.
Cutting a square hole in sheet metal.
How to use chisels instead of files to cut a share hole for carriage bolts.
Tap your hammer to leave an indentation on the sheet metal.
1 point 5 years ago.
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If the hole is a lot bigger then your biggest drill bit then drilling holes round the edge of the square and then connecting them with a saw is the best way for you.
Depending on the tools you have you ll now need to punch or drill a hole where the indentation has been made to produce an accurate hole in your sheet metal.
Blacksmithing for beginners cutting a square hole in sheet metal.
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Updated better method here.
Go slow and drill a smaller hole first ti guide the bigger rill bit.
Drill a hole large enough for a jigsaw blade in the part you re cutting out then cut it out with the jigsaw you ll have to curve into the straight lines of your square hole and do a little whittling but it works.
Ensure you fix the metal sheet down when you drill do not hold in you hand.
Place your sheet metal on your steel block and position your centre punch at a central point in your cut out design.