Classic Doorknob with Key - Illustration of Traditional Door Lock Mechanism #87148 (License: Personal Use)

This black-and-white line drawing depicts a classic cylindrical doorknob with a key turned in its lock, set within a rectangular metal backplate secured to a textured wooden door. The adjacent latch mechanism includes two square cutouts for bolt engagement, suggesting a functional mortise lock system typical of early 20th-century residential doors. Fine cross-hatching adds depth and realism to the wood grain and metallic surfaces.

Used in articles about historic home restoration, locksmithing basics, architectural hardware evolution, or educational content on mechanical locks; targets DIY enthusiasts, historians, and security professionals seeking visual reference for vintage door systems.