For pull-over, the fastener's head is pulled completely through a metal sheet. The 2005 Aluminum Design Manual includes an equation for nominal pull-over strength. This was based on testing using thin aluminum (1.02 mm maximum). Later, other testing indicated that this equation becomes increasingly conservative as thickness increases beyond 1.02 mm. A new equation has been developed that is in substantially better agreement with tests that used prescribed hole sizes and aluminum thicknesses of 1.02 mm and greater.