To be used with all FSB Thumbturns and Turn and Release Sets which have a 3⁄16″ (5 mm) diamond spindle.
Proper alignment of the FSB thumbturn subrose over the hub of the mortise lock or tubular latch is critical. Mis-alignment of the subrose can result in deadbolt malfunction once the thumbturn is snapped in place.
To avoid this issue from occurring, please use the thumbturn alignment tool provided in every appropriate FSB lockset or deadbolt set to mark the locations of the screws before fastening.
