Question MB Stand-Off Rant

Mantrid-Drone

Senior member
Mar 15, 2014
336
40
91
Why is that case and MB manufacturers have not put their collective heads together to support a single standard stand-off size and specification?

I ask this because that if I accidentally lost one of the stand-offs supplied with my new Fractal case it would be near impossible to get a correct size replacement except from Fractal themselves.

But they're not alone in this - I've had experience with three different cases made by three different manufacturers and they all use different size stand-offs.

One of them uses M3(M)/M3(F) 8mm height + stud length ie. the screw 6mm. This is the only one you can easily find replacements for mainly because it is all metric.

The other two are barkingly mad design decisions in that they use a metric M3 and #6-32 UNC mix for the (M) and (F) screw sizes. Worse they're the reverse of each other too ie. one has a M3 MB screw and a #6-32 receiving screw thread and visa versa.

The Fractal stand-offs further annoy by having a just under 4mm length stud and 8mm long hex stand-off body.

I've not found any third party stand-offs, even M3/M3 replacements with that combination of stud/body size.

It annoys me that there is no metric standardisation for such uses because it makes no sense that a PC case uses, for no good reason I can think of, stand-offs that are M3 at just one end. It would make more sense if they were #6-32(M)/#6-32(F).
 

mindless1

Diamond Member
Aug 11, 2001
8,058
1,444
126
There was one, then manufacturer decided to do their own thing.

I don't even remember exactly what it is, but I have a bunch of them screwed together into long rods in my bits 'n pieces computer parts drawer, I mean far more of one size than any other misc sizes. I think maybe 6/32 on the male end, M3 on the female, and don't know the length, maybe 8mm or 10mm.

If all else fails, just make one work. If you have the right length, you can turn it backwards, use existing motherboard tray hole or ream it out to a larger diameter, put a screw through the back side of the tray into the female end of the standoff then through the male end extending through the motherboard hole, put a nut on it.

Another option is grind off the rear lip on the motherboard tray hole so you have a few more thread turns purchase with a nut you put on the back of the tray onto the male threaded end of the standoff.

Depends on the case, and what you have lying around to use... but yes it is very annoying when standards aren't followed and a simple thing turns into a project.
 

WilliamM2

Platinum Member
Jun 14, 2012
2,372
479
136
I've only seen two sizes (length) of motherboard standoffs, and two tread sizes. The standoffs in my Fractal Define R6 are the same as many others I have used. I have both sizes, with both screw thread sizes in my collection of parts.
 
Last edited:

Mantrid-Drone

Senior member
Mar 15, 2014
336
40
91
I've done similar myself - one of the cases I used did not have a standoff screw hole beneath one of the ATX MB's mounting points. I was told this didn't matter but was not convinced as the distance between the two nearest stand-off positions was significant.

With a heavy cooler exerting a significant levering compression force down the board I decided to mount a stand-off through the MB with the screw (stud) cut off and filed flat so it was supporting the MB at that point against the MB case mounting tray.

In this case I can think of other solutions similar to what you've suggested. I was thinking why not just use an 8mm hex spacer ie. (F) threaded both ends M3 or #6-32 or whatever and mount it with an appropriate length screw through the tray. I've not checked whether that is possible in this case but would be a good solution if it is.

Maybe the stud length doesn't matter and you could use a 8mm + 6mm (M) replacement stand-off instead. But surely there must be a reason why Fractal decided on a 8mm + 4mm (M) stud length when 6mm is the commonest size used whatever the stand-off height.
 

Mantrid-Drone

Senior member
Mar 15, 2014
336
40
91
I've only seen two sizes (length) of motherboard standoffs, and two tread sizes. The stadoffs in my Fractal Define R5 are the same as many others I have used. I have both sizes, with both screw thread sizes in my collection of parts.

It must depend on the case/manufacturer and if you have used ones in the past and have saved the stand-offs that was the sensible thing to do. But the fact is they're not a common size assuming they're the same as supplied with my new Define 5.

The screw length is 4mm M3 and all you need to do is go on Ebay and try to find any 8mm height M3 4mm stand-off being sold individually or as part of stand-off kits. As said, almost all use the 6mm screw length.

Whether the (F) thread is M3 or #6-32 doesn't really matter as you can find suitable screws in either size.
 

WilliamM2

Platinum Member
Jun 14, 2012
2,372
479
136
It must depend on the case/manufacturer and if you have used ones in the past and have saved the stand-offs that was the sensible thing to do. But the fact is they're not a common size assuming they're the same as supplied with my new Define 5.

The screw length is 4mm M3 and all you need to do is go on Ebay and try to find any 8mm height M3 4mm stand-off being sold individually or as part of stand-off kits. As said, almost all use the 6mm screw length.

Whether the (F) thread is M3 or #6-32 doesn't really matter as you can find suitable screws in either size.

Sorry I typoed, I have an Define R6. It has 6mm standoffs, the others I have are 8mm. I've never seen any other size. 4mm is odd. Have you tried contacting Fractal? They've been pretty good when I needed parts.
 
Last edited:

Mantrid-Drone

Senior member
Mar 15, 2014
336
40
91
I have been thinking about doing that to ask whether the short 4mm 'stud' length is important.

I've spent the morning checking out all the stand-offs I have and I can 100% confirm that the Fractal ones are #6-32 (M) and the receiving (F) hex body is M3.

The sizing is roughly 4mm (stud screw)/8mm height (hex body) but is actually, as close as I can measure it with a steel rule as I don't own a micrometer: 3/20" (0.15") and 5/8" (0.625") respectively.

Of the eight other stand-offs types I've bought or were left over from my two previous builds and re-casing projects there's a big mix of sizes and specs. I won't bore people listing them. But there are M3/M3, #6-32/#6-32 and others like the Fractal dual standard ones.

Its the lack of standardisation that is the problem. Would it really be a serious hassle for PC case manufacturers to use one commonly available world wide all metric M3 stand-off size for mounting PC MBs?
 

lakedude

Platinum Member
Mar 14, 2009
2,549
265
126
I ran into this between 2 cases from the same brand. I needed one extra standoff for a new motherboard in an Antec 900 case. When I grabbed a spare standoff from an Antec Sonata case it was different. Not finding a match I had to replace all the standoffs so they would all be the same.

I had previously assumed standoffs were standardized, as they should be.

If I'd have known they were different I'd have saved the Antec 900 specific ones.
 
  • Like
Reactions: Mantrid-Drone

WilliamM2

Platinum Member
Jun 14, 2012
2,372
479
136
The sizing is roughly 4mm (stud screw)/8mm height (hex body) but is actually, as close as I can measure it with a steel rule as I don't own a micrometer: 3/20" (0.15") and 5/8" (0.625") respectively.

I'm confused, I thought you meant the hex body was 4mm tall. 8MM tall is the most common I've seen. The stud length doesn't matter, just the height of the hex, so the board lines up with the back of the case.
 

Mantrid-Drone

Senior member
Mar 15, 2014
336
40
91
As said the hex body, which is the height of the stand-off when screwed into position, is 8mm. The stud ie. the screw is 4mm in length and that is part of the trouble because in general stand-off listings for a 4mm screw length appears not to be as common in stand-offs as 6mm.

Add to that an uncommon hex body height and the requirement of the stud being #6-32 and the receiving (F) screw thread being M3 and its understandable why its difficult to find third party stand-offs of the correct spec.

I actually have four black stand-off which I bought years ago to use as MB supports for cases that don't include tray mount positions under all MB mounting holes. They are 11mm main hex body height with a 4mm stud, the male screw length.

The Cooler Master 330E case which is the first one I used: the stand-offs are 6.5mm hex height with 4mm studs both (M) and (F) are #6-32. They're actually described like that in the manual mixing metric and UNC measurements.

There's apparently no recognised convention in stand-off listing and where they do list the stud length as well as the stand-off ie. body height most commonly it uses the template:-

screw thread type/main hex body height/stud screw length

eg. M3/8mm/4mm sometimes they do it the other way round or M3 8mm + 4mm or similar variations. But there's no consistent way in any sales listing I've found for types where the screw threads for the (M) and (F) parts are different.

Obviously, I think, for any MB you must use a stand-off of the correct height or the MB back-plate is not going to be in correct position for the case. But whether the stud length is critical there's zero information I could find.

A longer screw length could be fine with some trays but with others might perhaps foul the cables routed behind it or even the right side case panel. Potential for trouble and you must assume that if the stand-offs that came with the case have 4mm length studs they were are that length for a good reason.
 

Mantrid-Drone

Senior member
Mar 15, 2014
336
40
91
Yes but wouldn't it be easier and cut down manufacturing costs if all PC case and MB makers used the same measurement system for everything (M3) and a common stand-off size or limited range of sizes depending on the form factor?

Alternatively do what Corsair do (or did with the Carbide 200R) and actually build in the ATX stand-off into the tray pressing so all you need is the correct MB mounting screw size whether that be #6-32 (what theirs are) or better. IMHO, M3 but both commonly available world wide.
 

ch33zw1z

Lifer
Nov 4, 2004
37,766
18,045
146
Yes but wouldn't it be easier and cut down manufacturing costs if all PC case and MB makers used the same measurement system for everything (M3) and a common stand-off size or limited range of sizes depending on the form factor?

Alternatively do what Corsair do (or did with the Carbide 200R) and actually build in the ATX stand-off into the tray pressing so all you need is the correct MB mounting screw size whether that be #6-32 (what theirs are) or better. IMHO, M3 but both commonly available world wide.

sure, but it’s never been like that. At least we have standards like ATX, mATX, etc…anyone remember BTX, lulz.

I don’t know if making that change would cut down on costs or not, but it could certainly cut down on user frustration
 
  • Like
Reactions: Mantrid-Drone

aigomorla

CPU, Cases&Cooling Mod PC Gaming Mod Elite Member
Super Moderator
Sep 28, 2005
20,846
3,189
126
you want them to get standoff's uniform standardized when the screws that even screw on the standoff's they can't agree on either M4 or 6/32, with the messed up political balanced vendors using BOTH the metric and customary on even server applications for no apparent reasons other then just because its enterprise.
 

Mantrid-Drone

Senior member
Mar 15, 2014
336
40
91
As I said standardising on M3 for both male/female standoff threads makes the most sense.

How many people even know what #6-32 even means let alone #4-40 also found used for some standoffs. Its mad having dual measurement system being used for this sort of technical purpose.

Believe me I'm not blindly pro-metric - in the UK I'm of the first generation taught using the metric system in school so swapping between the two was part of my upbringing. Give me mph rather than kmph, pounds and ounces for cooking and the other casually useful 'imperial' measurements in preference to their absurd metric equivalents any day.

But for precision, science, engineering and manufacturing etc metric should rule.
 
Last edited:
  • Like
Reactions: aigomorla

BonzaiDuck

Lifer
Jun 30, 2004
15,725
1,455
126
I had the same problem with a lack of standoffs altogether in a used CM Stacker 832 I bought on EBay.

We have, in my city's industrial block north of town, an Electronics Warehouse that serves "jobbers" and other customers. I just went down there and bought the right standoffs.

Oh -- the case had a couple of the right item, but the rest were missing. So I was able to match what I had with the offering at the store.