[FraGGleR]

I feel silly asking, but I hadn't had to think about them before.  Anyways, are there any standard standoffs that people use? Steel?  Aluminum?  I have only ever used circuit boards designed to slide into enclosures.  Thanks!

 

[DingoSmuggler]

Most commonly used would be hex standoffs (hexagonal body, with pre-tapped threads).
Of those typically would use a female-female standoff which allows screws from both sides (chassis and pcb) - use a lock washer on the chassis side so you don't undo it while tightening/loosening the pcb side.
You would use a male-female standoff for the 2nd tier if stacking boards.
You'd also use a male-female if tapping into a chassis or heatsink etc.
 
Materials typically steel or brass and usually plated in zinc or nickel.
Aluminium standoffs can have a wider cross-section so might not suit particular applications, plus its easier to cross thread so i would not use aluminium personally unless there was a particular need for it.
 
M3 would be the most commonly used thread for a lot of projects or #4-40 if you're still living in the dark ages *insert smiley here*
But mostly get the standoff that suits the particular project your undertaking.

 

[FraGGleR]

Thank you very much.  That helps me sort through the Mouser list much more easily.  

 

[DingoSmuggler]

Quote:

Thank you very much.  That helps me sort through the Mouser list much more easily.  

Actually it looks like aluminium is a reasonably popular choice for standoffs too, looking at other projects & listed BOMs etc. I've always bought steel or brass, probably me just being overly cautious. Anywhere i buy goodies from, the Al ones aren't any cheaper, but at mouser they seem to be a lot cheaper.
 
Also my *dark ages* comment may have been a little cryptic, what i meant by it was the world tend to use M3, USA like to use 4-40 UNC (availability and price probably better for you).

 

[wdahm519]

Honestly if you want a cheap standoff that is customizable to ANY height:
 
Pick your favorite length 4-40 machine screw. Then drill a hole through the bottom of your chassis that is "close-fit" for a 4-40 (#32 drill bit). Put the 4-40 screw up through the hole into the chassis and secure it in place with a 4-40 nut. Then with a pair of nuts on the threaded shaft of the 4-40 you can float your board in mid air and tighten it down. Just try and put all four corners to roughly the same height for obvious reasons.
 
I do this all the time, works wonders.

 

[FraGGleR]

Thanks guys.  I like the idea of using screws as adjustable height standoffs.  I will try that.  

 

[SiBurning]

Plastic standoffs work well with screws & nuts, and you only need one nut. Connectors--like IDC, edge connectors, or matched sets of inline pins and sockets--can also be used as a standoff, and they can also carry signals to a daughter board, even if they're not quite the right thing for mounting to a case.