You need to go to a proper engineeres tool shop or store.
ask to see and try aviation hand shears so take your sheet metal
They are a precision tool, with multiplication to make cutting
easier and strong enough for all you might want.
your Harbour Freight depot is not the place to look for quality
The days of lots of properly made USA tools is fast disappearing.
Not quite as bad as that here in the UK. We too have a problem
finding quality as in 1950’s or earlier, made tools.
They are about, but you have to go to yard sales every week to hunt
Whenever I see them, I buy them ever if ive already several pairs of
what ever, shears, boxwood handled wood chisels, morse taper shank
drills, early hammers, all small center punches and chisels for the
steel, and as mentioned before bigger stuff like mills, presses,
anvils, leg vices electric motors ie 1 HP upwards. etc.
Even if one never uses them there always a trade item with other
metal smiths for something one might really want.!! Keep hunting and
become a tool junkie!!