Steel is incredibly tough. Thankfully metal shears were invented that can cut through metal like it was paper. We started off using a jigsaw, and then finally purchased a throat-less shear. What a difference! Production time was greatly reduced and our cutting accuracy went through the roof. Princess Auto is a great place to find a throat-less shear.
Steel comes in different thicknesses expressed as a gauge (ga). Your shears should be able to handle 14ga. 12ga = .1046in = 2.656mm 14ga = .0747in = 1.897mm 16ga = .0598in = 1.518mm
You can use electric shears for metal cutting. We bought one and found that if the sheet metal was at all bent it didn’t work very well. In the end, the one we had snapped in two and was toast. It was a cheap tool, so a better quality one might work better.