They were 2" exactly measured from the sharp edge on the side of the slotted head to the end point. The shank was smooth for the first 5/8" or so from the head down. Most reissues that I've seen have threads that go all the way up. I have an original neck plate and slotted screws that wiuld be correct for a broadcaster right now on eBay as well as some other 50's tele parts. See link attached!