I have no idea what some of you are talking about on this very elementary trigger project. 1/8” X1” hot rolled strap from the welding shop is incredibly easy to form cold. It should have no problem with any sized trigger plate thickness you can conjure up, because it simply fits through a slot in the plate, and pins through the stock. This really is not rocket science, I literally made my first basic trigger with stuff from the scrap bin.
Before you buy a bunch of special stuff, try making one from junk for practice. It about an hour project with a beer break.
Hungry Horse