Mortise Locks FAQs Mortise Lock FAQs Is there a mortise lock offering for doors thicker than 2.5 inches? Yes, however it will need to be placed through a special order and you will need to contact SARGENT technical service for more information. Close Does SARGENT offer narrow back set mortise locks? No, currently we only offer SARGENT mortise locks with a 2 ¾” back set. Close Can I use trim from the older 8100 Series on an 8200 Series mortise lock? No, the attachment design is different. Close