WEST 916

The 916 is a dimple lock made by the Japanese company WEST. It contains 12 pins, arranged in two opposing rows of six on the left and right of the keyway.

'' Please note: the 916 is very similar to the larger, 20-pin WEST 917 model. The two locks share the same pins, fundamental designs, and primary security features.''

Principles of operation
The WEST 916 utilizes dimple keys but functions the same as a standard pin-tumbler lock. The lock uses 12 chambers for pin-tumbler stacks. Each of those chambers contains a set of key pin, driver, and spring. A seventh chamber on the right side of the bible contains a sprung bearing that aligns with an indent in the core to center-bias it.

The dimple key of the 916 has four cut depths for key pins. The key is bitted on the sides of the blade and is reversible. To open the lock, all 12 pin-tumblers -- across both rows of pins -- must be aligned at the shear line. (See also Pin-tumbler, Principles of Operation)

WEST utilizes a variety of security pins to deter picking. Pin stacks incorporate stainless steel key pins with two sizes of brass driver pins to match. The 916 uses a mix of mushroom spool drivers and standard ones. Drivers are cupped to allow the spring to nest inside the pins. Key pins are a combination of t-pins and multi-section tapered spools which are torpedo shaped to create overset traps. These pin designs match overmilling of the pin chambers in the core to catch pins as they are lifted to shear.