Quote Originally Posted by John Vernier View Post
It seems like most of the modern saw makers are using 1095, and everyone seems to agree that it is harder (that is, harder-wearing and harder to file) than older manufactured saw plates. So 1075 might be closer to the carbon content of good earlier saws, and could work just fine, though it might need sharpening more often than the 1095. Much depends on the tempering, of course.

I measured the plate thickness on two older bow saws which I have. A Peugeot Freres rip saw with a blade about 2 feet long and 1 1/2 inches wide is 0.28 thick; an older German or Scandinavian turning saw with a blade about 2 feet long and 1/2 inch wide is 0.26 thick. The plate you have does seem on the thin side, but might be worth a try since you have it - at least it will give you some practice filing even teeth. I should think you want to cut quite fine teeth with a bade that thin.
Sawplate hardness is determined by both the alloy and the temper. 1095 is Rc65 or so as hardened, but can be tempered all the way down to Rc30. The corresponding range for 1074 is Rc59 to Rc25 IIRC.

EDIT: See George's post above.