Modding Thread type?

For my DivX BoX HTPC I will have to mount the mainboard on custom drilled/cut akuminium plates. I'm going to mount it with the standard mainboard mounting screw thingies, only I need to know what type of thread (is that the right word?) they use (e.g. M3). Anybody know?

 

*Bump*

 

Well i've just learnt that the M3 for example is a thread that is 3mm in diameter. So measure the hole that your bolting thought and find out the diameter in mm and thats your M(Diameter) size.

 

You need to know how many threads there are per inch as well which is like eg 3/32 or something...

 

what so for a 3mm diameter, 10mm long and 32 threads per inch it would say..

M3x10/32?

 

No, if it was a 3mm bolt, it would be millimeters per thread, not threads per inch. An SAE bolt may be 10-32xwhatever length. In that case, the 10 is the diameter in 64ths, 32 is the threads per inch. The metric bolt you're describing would more likely be 3x.5mm, 10mm long.

 

Ok... Well I still havent gotten smart about this thread... There are so many different threads (metric, UNC, UNF, etc.). The mainboard mounting screws are all the same, doesn't anyone know the exact thread of them? (I'm probably just acting pretty stupid because of really bad jetlag).

 

there was another thread here not long ago asking for the same thing... i can't remember what threads it was....

 

Definitely not stupid. For some reason the standard hardware for computers is kinda confusing. Pretty much everything is either 3x.5mm, or sae 4-40. Must motherboard standoffs I've seen screw into an sae 4-40 hole, but take a 3mm screw

 

well i thought knew about it but i'm totally confused now

 

LOL! Sorry to confuse you If you grab a bunch of computer screws, you'll notice they're either a bigger, course thread, or a smaller, finer thread. The slightly bigger of the two is a 4-40 thread. That's an SAE #4 screw with 40 threads per inch. The other is a 3mm screw with 0.50mm per thread. Usually, floppy and some hard drive mounting screws are the smaller 3mm, while the case cover mounting screws and most cdrom mounting screws are the 4-40.

 

I'm getting the feeling, that we are not talking about the same thing, so I took a picture, of what I mean:



And look at that! There are different types of these things with different threads... Always thought they were all the same.

 

actually the majority of screws on the computers are 6-32 threaded... motherboard screws (the tiny ones that screw into the standoffs) are M3 if i remember right

 

cderalow is probably right. So the one on the right is 3mm, and the other is 6-32.