This is a new Best Lock Company combinated, interchangeable test core. It is 6 pin, F keyway, and it is 626 (satin chrome) finish. It is keyed using all original Best pins (no colored pins). The purpose of a test core is to speed installation times for Best locks by not requiring the use of two keys (both control and operating keys).
This core operates on a principle that was developed by Frank E. Best, Best Lock Company founder. He was also the inventor of the first interchangeable lock system in the early 1900s. This core is specially combinated so that one key serves as both the operating key and control key. When the key is inserted all the way into the core, it functions as the operating key. However, when the key is withdrawn one space (or notch) and turned slightly to the right, the key functions as the control key. The core cuts down the amount of time required to test Best locks during installation, as only one key is needed (instead of two keys).
Included will be one original Best key that is stamped "It is unlawful to duplicate this key." Best has not used this key stamp for several years, and it is no longer available.
Presently Best Lock Company charges more than $30 for one combinated core. Here is a chance to obtain an original Best core that was made in the USA.
