M4 definately is too big. Tried M3, should be allright if being used only to fasten the fan onto the radiator.
My case, the whole radiator is being hung at the back of the casing with 4 long M3 studs.
Doesn't seem OK with M3 size, the orientation looks to me like the radiator will fall off anytime
Haven't tried 6/32, the unit looks to me like US customary thread, I believe the M3 n M3.5 r metric.
Added on October 28, 2010, 10:47 pmQUOTE(lichyetan @ Oct 28 2010, 04:51 PM)
6/32 best for swiftech... some holes is to big for m3... while swiftech web state 3.5 or 6/32...
I got older mcr220qp cant use m3, but now using slightly newer mcr320qp can use m3 pulak, but some not suitable for m3, really

This could be due to the standard is not being globalized. They happy, they produce M3.5, when they r not happy, they produce M3.
I don't know what is the root cause of this small matter.
This post has been edited by J1@l_ l_l l\l: Oct 28 2010, 10:47 PM