how thick will gilbow 10" tinsnips cut in mild steel sheet?

Many Thanks

About 1.2mm iirc

I've cut 16g with mine but it's hard work if you're not just trimming the edge off something, they will cut 20g like paper. The problem is getting the waste side of the cut out of the way. I use a drill powered nibbler I bought at a show for £30, it cuts 16g easily as long as you oil the cut line.