In short yes. Check out this BOL subject
ms-help://MS.SQLCC.v9/MS.SQLSVR.v9.en/udb9/html/68ae44ef-990c-49c2-b502-ff1dc41b4019.htm
You can copy column properties from a primary key column to a foreign key column if you want to relate the two columns. Related columns must have the same data type (or data types that can be related) and length.