What are the maximum Bytes per Primary Key in SQL Server?

table.hovertable {
font-family: verdana,arial,sans-serif;
font-size:11px;
color:#333333;
border-width: 1px;
border-color: #999999;
border-collapse: collapse;
}
table.hovertable th {
background-color:#c3dde0;
border-width: 1px;
padding: 8px;
border-style: solid;
border-color: #a9c6c9;
}
table.hovertable tr {
background-color:#d4e3e5;
}
table.hovertable td {
border-width: 1px;
padding: 8px;
border-style: solid;
border-color: #a9c6c9;
}

What are the maximum Bytes per Primary Key in SQL Server?

SQL Server Supports 900 Bytes per Primary Key.

Max Capacity For SQL Server 2012 SQL Server 2008 R2 SQL Server 2008 SQL Server 2005
Maximum Bytes per Primary Key in SQL Server 900 900 900 900

http://msdn.microsoft.com/en-us/library/ms143432.aspx