Question Fan screw diameter and thread pitch?

[jonnyguru]

You would think this would be an easily answered question, but I can't find the answer anywhere!

Apparently I have two different fan screws with two different thread pitches.

I know one is 5mm diameter, with a T16 pitch. The other is 4.9mm with a T14 pitch.

What does T16 and T14 actually mean? And which one is "standard"?

 

[tennis2]

I usually see T16 / T14 as a reference to Torx screwdriver heads...

Fan screws.....? For mounting them to a radiator?

 

[jonnyguru]

I usually see T16 / T14 as a reference to Torx screwdriver heads...

Fan screws.....? For mounting them to a radiator?

The screw that taps into the fan frame.

Like these: https://www.amazon.com/Kenable-Case-Screws-Mounting-Tapping/dp/B00PEKMHBQ

I have spec sheets from two different manufacturers. One says the thread is T16 and the other says the thread is T14.

And no, I'm not talking about Torx.

 

[tennis2]

Not sure why they're labeled with a T prefix. But threads are typically represented as threads per inch. In metric, it's distance (mm) between threads (measure peak to peak). 14-16mm between thread peaks isn't right though for those screws.

I also thought that metric was 5mm, 4mm, 3.5mm, 3mm, etc etc. 4.9mm seems strange.

 

[popatim]

Self taping M5 screws are the classic fan screws.

 

[tennis2]

T= trapezoidal threads? Usually denoted by TR__x__

 

[jonnyguru]

I also thought that metric was 5mm, 4mm, 3.5mm, 3mm, etc etc. 4.9mm seems strange.

Nope.

Example: https://www.pencomsf.com/product/fan-screws/fan-screws/

Note the M3.9, M4.2, M4.9.. Problem with this site is they say nothing about thread pitch and the two screws I have are different pitch.