Best thread for All

[GSRocket]

Hi Guys.......For best holding power in Aluminium is course or fine thread best?

[Clubman7]

Lots of scope there for answers.
Normally a fine thread is stronger.
If its a hole that your talking about, you can fit a thread insert into the hole and this will
provide extra strength for what your screwing into it.

[GSRocket]

Lots of scope there for answers.
Normally a fine thread is stronger.
If its a hole that your talking about, you can fit a thread insert into the hole and this will
provide extra strength for what your screwing into it.

It's not a critical application, it's just that at the moment I have a choice and a lot of holes will be made. It's only a 5mm hole.
I know in steel fine is best...It's just that I vaguely recall or read or something from somewhere that because it's a softer material course was best.

[nadroj]

Fasteners for aluminium alloys are almost always of a coarse thread.
The only exception I've seen was when the thread provided a means of fine adjustment. For example, on a motorcycle gearbox casting (to adjust the input drive chain's tension), and its 5/16 x 26tpi thread is prone to stripping (the gearbox, not the adjusting bolt).

Jordan

[Gerbilsquasher]

+1 coarse thread

[shedhappens]

+1 coarse thread

...and for more strength you would use a stud so that you are less likely to pull the tread out when tightening

[GSRocket]

Thanks guys.................It's good to have a vague memory confirmed