Question: What is a Yale GST key blank? Answer: Yale GST blanks are a multi-sectional keyway. Typically a Yale cylinder is assigned a single letter or two letters. I.E. G, GA, GB, GC, etc. The G key blank is a master milling that will fit in not only the G cylinder but also all cylinders in that sequence. The Yale GST blank fits all G, S and T keyways.   In addition to a broad offering of product and service solutions, IDN offers pre-sale and post-sale technical support.  The benefit to you is that We Make Security Simple.  Whether your task is related to high-security systems, electronic access control, door installation, or other, our experts are here to assist.  Just let us know how we can help.  Do you have a question, or need a quote? Contact your local IDN Branch, or ask the Key Wizard through our website. © Copyright IDN, Inc.