>>18930355

Commercial building are often keyed in layers of protection allowing individuals, managers, and maintenance personell to have local, area, master, and grandmaster keys

The "key" to managing these security systems is in the coding book for how to "makeup" the pins and keys.

>>18930390

In my experience, when removing the core, the pins often fall out, so a long skinny pair of needle-nose pliers are useful for twisting the shaft to slide the bolt.

But core keys do make life much easier.