Bottom pins that are made of nickel silver, or nickel plated, don’t wear as easily as brass pins, especially when using a nickel silver key. Some cylinders in your system could get used hundreds of times a day. If a nickel silver key is used in an application like this, and the cylinder contains brass bottoms pins, those pins will wear extremely quickly. This reduces the life of the cylinder, could cause unnecessary lock-outs, and requires additional maintenance and service to key the cylinder functioning properly consistently. Language to use in key system specification:The manufacturer’s bottom pin segments will be required to be nickel silver or nickel plated.