May 20, 2026 5 min readBy Tim, Open Sesame Lock & Key
A master key system lets one key open every door while each staff key opens only what that person needs. The mechanics are simple; the planning is what separates a system that lasts from a drawer full of mystery keys.
How it works
- Each cylinder gets an extra split in its pin stack, creating a second height at which it will turn. Your change key hits one height; the master key hits the other.
- Keyed-alike is the simpler cousin: several doors, one key, no hierarchy. For a small shop that's often all you need.
- Grand master systems add another level above the master — worth it for multi-building operations, overkill for one storefront.
Plan before you pin
- Walk the building and list every door, then decide who genuinely needs each one. Access creep is what kills systems.
- Group by role, not by person. 'Kitchen staff' survives turnover; 'Dan's key' doesn't.
- Decide now what happens when a key isn't returned — which cylinders get rekeyed, and who pays.
Keep it maintained
- Hold a written key chart listing every cut, cylinder, and holder.
- Use restricted keyways if uncontrolled copying is a real risk — those blanks can't be duplicated at a hardware store.
- Rekey the affected level whenever a key goes missing, not the whole building.