misterj wrote:Hey Everyone-
Did older Corbin locks have ball-bearings on top of the pins? (dated late 1950s)
Yes. 1902-1960's .116" ball bearings were inserted to reduce wear until harder brass was available for key blanks. All five chambers of Corbin and Russwin used to contain ball bearings until 'lock combing' became an issue. Ball bearings wear gradually reduced until only the first two chambers contained them. The older the lock, the more the bearings. SK1 is the Curtis/esp/Ilco number for original 77-5 Corbin keys. 77-5 was an original X class keyway, so it is old. You still see SK1's because they were widely used. I don't know the exact date of the incorporation of the front two chambers using the ball bearings.
All the information above is taken from the Corbin cylinder manual.