I have 3 external doors on my house. Each has a different key. Two are Schlage sets and one is a Norwalk. The Norwalk blank says AR1 on it, and the Schlages are the standard version. Is there a way to have all the locks share a common key?


 ![lock][1]
 ![lock][2]
 ![lock][3]
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  [1]: https://i.sstatic.net/L58O4.jpg
  [2]: https://i.sstatic.net/FNPRK.jpg
  [3]: https://i.sstatic.net/vGiiO.jpg
  [4]: https://i.sstatic.net/DKgRv.jpg