yogibayer wrote:This is an old Yale Mortise Lock and the (outside) knob appears to have a set screw hole in it, but whatever is in there is completely flat with no slot or phillips screw head. There are no similar holes on the inside knob. Any help in identifying what model of lock it would be helpful too.
What is the issue with that lock which requires you to remove the knob ?
That lockset in use in a commercial building, is it broken or something ?
As far as what type of lockset you have there it looks like a Yale 8847,
ANSI Function 20 (Entrance or Apartment Door Lock) with a deadbolt
function as well as stop works to allow the outside knob to be unlocked...
Care to describe in more detail what the problem with the lock is ?