Originally Posted by Raider2000
I think he means to have the Cylinder Pin threaded or sloted to keep lubricant on it for a Remington copy or a Ruger OA.
Ok, that would make sense. In that case we need to say that the Colt arbor is slotted, not threaded, and that the purpose is indeed to hold lube, I believe. The Remington 1858 New Army/Navy does have a flat side for the same purpose, although it is not as effective. I don't believe the Ruger OA has such a device but mine has never bound up so I can't say I ever checked to see (I'll look tomorrow).
WRT the Remington, I'd be concerned that slotting the arbor/cylinder pin would weaken it considerably, so it doesn't seem like a good idea to me.