Windows & doors · definition
A lock bolt thrown by a key or thumbturn (not spring-actuated), the primary security lock on an exterior door. Grade 1 is the highest residential rating.
Source: Therma-Tru — Glossary of Common Door Terms
Where this term lands on a Columbus budget
The cost pages carry the current local ranges, and the guides explain what moves them. A published range becomes a project number only after someone looks at the site.