Yes, smart locks can be installed on any type of door, including metal security doors. In fact, many smart lock manufacturers design their products to work specifically with these types of doors due to their increased security features. Installing a smart lock on a metal security door not only adds an extra layer of convenience when entering and exiting your home but also enhances your property's overall safety and protection.   I recently upgraded my home's front entrance with a smart lock installation that was compatible with my metal security door. The process was straightforward, and I was impressed by how seamlessly the new device integrated with my existing locking mechanism.