Posted by Tom Martin on June 28, 2017, 9:19 pm, in reply to "5 Pin Variation"
I dislike seeing the "x number of pins" descriptions because that is a bit of Brit terminology that causes confusion. The Brits call screws "pins", whereas we don't, in normal US terminology. There is no difference in the number of screws and pins in the 1907 locks and earlier or later locks. The difference is that some screw holes in the earlier and later locks are blind holes that are not drilled and tapped all the way through. On the 1907 locks the holes are drilled and tapped all the way through the lock plate, and the ends of the screws are domed and polished, so that when the locks are viewed from the outside, they appear to have more pieces, when in reality they don't.