Phillips head screws for installation  of fans on radiators. For flat head screws, the dimension refers to the actual length of the thread. Countersunk screws at the entire length is specified. These screws can be used to the radiator with fans and fan grills to be attached to  a housing. The M3 thread is compatible with (as of 05 2006):

NexXxoS Pro
NexXxoS Xtrem
Airplex Evo

Material: stainless steel

Important: These screws should be used only in combination with a 25mm fan, as the screws are too long for the smaller fan and then damage the radiator. When used in smaller fans (20mm) aperture, a fan, then this course fit again.

Warning: may tighten further damage the Raditor, look for the correct length of the screws. Not in every case, these bolts fit