so far as i can see there are not needed, out of two durons that i have killed one from moisture and one from a pelt on backwords," duh" but no problems with cracking a core. i've had small chips that did not hurt the core. the best way to attach a sink is to use 4 bolts throgh the mobo and then use springs and nuts to give even to torque.
http://www.geocities.com/jamestune_2...l?947305781960