I was looking at some recent 58mm SD type files and noticed that there were two distinct types.
On the one type the side of the screwdriver tapers in from the file side and on the other type from the opposite side. The blade markings could not be used to distinguish between the ages of these files.
The ones with the taper on the file side had a slightly rougher and older looking file surface, so I assume they are older.
When did the change occur. I think I read about the change somewhere but Icould not find it...
The 3 on the right taper from the file side:

closeup (reversed)
