Mortise deadbolt, Grade 1, restricted keyway

A restricted keyway means blanks are controlled: a key cannot be duplicated at a hardware counter or a supermarket kiosk without the card that came with the lock. For a house that has had contractors, tenants, or a lost key, that is the difference between changing the lock and not needing to.

Grade 1 cylinder with hardened anti-drill pins and a one-inch throw. Ships with three keys and the duplication card. Losing the card means losing the ability to cut more, so put it in the chest on plate 22.

Fitting and care. Put the duplication card somewhere that is not in the house the lock secures — a safe deposit, a family member, a work drawer. Without it you cannot cut another key and the only route back is a new cylinder. Record the key numbers separately from the card. Fitting a mortise deadbolt means routing a pocket into the stile, which is a joiner’s job on a door you care about. Lubricate annually with graphite or PTFE, never a general oil, which will pick up grit and shorten the life of a restricted cylinder considerably.