What kind of Screws are use?  

The easy way is to take some with you and ask them to match your samples.   They are 'M' metric sizes, eg M3x20 = 3 mm by 20mm and are available with a wide range of heads and materials.

Cheerio,

RE: What kind of Screws are use?

For example my USB Hub have screwholes for USB Cable to screw in. Sadly the Company dont provide then with USB-A to USB-B so why not Print some sleve and screw the sleve in. The Screws I have for spare work to screw in. So that mean I need more M2? M3? ... Screws?!

I dont know what the Printer use for size sine the fit...

Can someone recommend a Video who explane an noob how to design something from scratch in Blender?
For the start I would like make an Custom Adapter for my (upcomming) Fans to my Pc. The Pc use a small 50x50 I guess and I will use 2x silent 80x80 for. Maybe make an Round Adapter to put an "old" Airfilter on Top who I blow clean with compressed Air so its quite ok for that useage.

RE: What kind of Screws are use?

You did not even write what printer you have. 😑

For technical construction CAD software (like Fusion360) is better suited than modelling software like Blender.

Fusion does contain CAD/E-CAD/CAM and modelling, Blender does contain modelling, sculpting, posing and animation.

Here is a good tutorial series for Blender. And here is a quick intro to Fusion.

RE: What kind of Screws are use?

I use the current i3. I want use Blender only for € reasion.

RE: What kind of Screws are use?

I don't know if this is the current state, but roughly it should be correct:

And Fusion360 is free for personal and educational use. There is also FreeCAD and other free CAD programs.

RE: What kind of Screws are use?

Plain old generic metric hex screws and nuts.

If you're in the States, few hardware stores stock a wide variety of these in the smaller (as in m3) sizes, but Amazon and the other usual suspect dealers will have low-cost assortments of metric fasteners.

RE: What kind of Screws are use?

Minor correction to my previous post: The picture shows an external hexagon head screw (DIN933), but only internal hexagon head screws (DIN912) are used.

RE:

Did you mean these. Socket head cap screws. 
https://www.mcmaster.com/screws/socket-head-screws/

RE: What kind of Screws are use?

I just bought screw/nuts/washer sets on amazon. Its ok cheap and you have good selection  for various situations.