Why do case fans come with self-tapping screws?

[giygaskeptpraying]

This was new and unexpected to me when I first ordered extra case fans, and I notice a lot of people asking about them online who have a lot of trouble with them. In particular I'm worried about messing up some Corsair fanss I just received, people have complained about plastic and rubber near the mounting holes breaking off, leaving the screw stuck halfway in with no way to remove it without destroying the fan.

 

[Alec Mowat]

I've threaded a few screws, but never broken a fan.

 

[bgunner]

the holes in the fan are not tapped when you buy them. The self tapping screws when used properly will cut threads in to the plastic and will hold tight.

to properly use the self tapping screws you need to screw them in a turn or two to start then back it off 1 turn then turn it 1 1/2 turn and back it off 1 turn then turn it 1 1/2 turns and repeat this till the screw is close to seating itself. Do this out side of the case. then insert the fan and attach with all 4 screws.

the reason for backing it off is so the plastic removed is moved out of the way so the teeth can cut cleanly and freshly.

 

[giygaskeptpraying]

the holes in the fan are not tapped when you buy them. The self tapping screws when used properly will cut threads in to the plastic and will hold tight.

to properly use the self tapping screws you need to screw them in a turn or two to start then back it off 1 turn then turn it 1 1/2 turn and back it off 1 turn then turn it 1 1/2 turns and repeat this till the screw is close to seating itself. Do this out side of the case. then insert the fan and attach with all 4 screws.

the reason for backing it off is so the plastic removed is moved out of the way so the teeth can cut cleanly and freshly.

Thanks for the tips, I'll keep that in mind.

Why can't the mounting holes in the fans just come pre-threaded though?

 

[bgunner]

because it is cheaper for them to supply the self tapping screws than thread the holes. it saves you money.

 

[giygaskeptpraying]

because it is cheaper for them to supply the self tapping screws than thread the holes. it saves you money.

I see. Would you recommend threading the holes first before attaching the fan to the case?

 

[bgunner]

because it is cheaper for them to supply the self tapping screws than thread the holes. it saves you money.

I see. Would you recommend threading the holes first before attaching the fan to the case?

yes I do recommend threading the holes first. this is because you will have a better hold of the fan while turning the screw. when tapping a hole, no matter what material, the object needs to be held still to prevent breaking the tool or causing improper thread spacing. In this case you can cause the head of the screw to strip because of improper pressure between screw and screw driver.

once threaded, just like any bolt or screw going into a threaded hole, be cautious of cross threading the screw. this can cause the screw to be hard to thread ans strip the screw head and the threads in the hole.