AM4 backplate thread size

[SL2]

I'd order a new backplate with included screws, would have been so much easier if I had no way of checking the thread.

 

[lorry]

I'd order a new backplate with included screws, would have been so much easier if I had no way of checking the thread.

screws won't be long enough, I want to use the backplate for the Optimus waterblock, so they need to be somewhere in the region of 25mm in length.
Now if you know how I can order them without knowing the thread type and size you is a better man than me gungerdin, or however you spell that
Seriously I am not happy putting That much pressure onto the MB without some kind of bracing

 

[SL2]

Oh, I see, It wasn't as easy as I thought.

 

[sneekypeet]

If you look around the internet, the consensus is that they are 6/32 by half, as stated by someone else earlier. You can go to damn near any online hardware joint and order them to lenght.

 

[lorry]

If you look around the internet, the consensus is that they are 6/32 by half, as stated by someone else earlier. You can go to damn near any online hardware joint and order them to lenght.

Now I can yes, but I Did look and there didn't look to be any confirmed sizing. If I had that info I wouldn't have bothered posting.
Whilst it was thought to have been M3.5 I looked, and found a Single place selling That size here in the UK

 

[sneekypeet]

Now I can yes, but I Did look and there didn't look to be any confirmed sizing. If I had that info I wouldn't have bothered posting.
Whilst it was thought to have been M3.5 I looked, and found a Single place selling That size here in the UK

Easiest way to confirm without question. Shoot off an email to a motherboard maker or five, and AMD. Someone will get back to you with the answer.

 

[lorry]

That very much doubt somehow mate.

 

[sneekypeet]

That very much doubt somehow mate.

TBH I have very little trouble reaching out via email or social media and get responses. Won't know till you try right? I mean, you may as well go to the source if you cannot confirm from what this thread already has.

 

[lorry]

I know that I won't know until it's tried, but given past dealings with gigabyte 'support' I have my doubts over it being successful. Worth a try though I know

Just got this BTW from Noctua, has no threads on it at all, so you can use whatever nut and bolt that you want up to M4 and IF you can bend this you'll be doing well as it is 2mm thick steel with an insulated back

Noctua NM-AM4-L9aL9i, Mounting Kit NH-L9a & NH-L9i on AMD AM4 platforms : Amazon.co.uk: Computers & Accessories

Buy

www.amazon.co.uk

https://imgur.com/nTCCuOY

Also I can put this one to bed, likely anyone else can as well. The bolts for the stock AMD AM4 bracket that came with my Gigabyte x470 Gaming 7 are 6/32

https://imgur.com/fPBRBvP

 

[moproblems99]

As the title says, I am trying to find out AM4 backplate thread pitch size (the thread that air and water coolers screw into).

I am not sure the size but I can also tell you that the backplates have different heights of the female thread area that protrudes through the motherboard. Board makers are supposed to supply the correct height backplate on request.

Edit: Also, if I can find my thread pitch gauges, I can let you know what they are.

 

[lorry]

I am not sure the size but I can also tell you that the backplates have different heights of the female thread area that protrudes through the motherboard. Board makers are supposed to supply the correct height backplate on request.

Edit: Also, if I can find my thread pitch gauges, I can let you know what they are.

It's ok now, thanks though, appreciate it. I found a Noctua AM4 backplate that does away with threads entirely (see above) and doesn't have any of those female threads protruding through. I can then use up to a M4 sized nut and bolt.

 

[Jazzer]

I know that I won't know until it's tried, but given past dealings with gigabyte 'support' I have my doubts over it being successful. Worth a try though I know

Just got this BTW from Noctua, has no threads on it at all, so you can use whatever nut and bolt that you want up to M4 and IF you can bend this you'll be doing well as it is 2mm thick steel with an insulated back

Noctua NM-AM4-L9aL9i, Mounting Kit NH-L9a & NH-L9i on AMD AM4 platforms : Amazon.co.uk: Computers & Accessories

Buy

www.amazon.co.uk

https://imgur.com/nTCCuOY

Also I can put this one to bed, likely anyone else can as well. The bolts for the stock AMD AM4 bracket that came with my Gigabyte x470 Gaming 7 are 6/32

https://imgur.com/fPBRBvP

I have been trying to fit an AM4 board and Ryzen 5 into a fanless, heat-pipe cooled chassis. Having solved the problem of the changes to the screw-hole placings between AM3 and AM4, I hit the problem that the original screws were the wrong thread. All I needed to do was obtain longer screws with the correct thread and use the original tension springs. (BTW, the stock cooler that came with the Ryzen 5 uses captive screws with springs secured by circlips which screw into the backplate, rather than one of the other two alternatives, one of which clips over the plastic brackets.)

The following is what I have found from my measurements. The original screws are 3mm and have a pitch of 0.5mm. This appears to be a standard size as my supply of machine screws fits the original board fittings.

The AM4 screws are 3.5mm and have a pitch of 0.8mm.

3.5mm is the standard screw to fit wall sockets in the UK, so they will be easy to source, won't they? Unfortunately, not. The standard for 3.5mm screws is a pitch of 0.6mm.

The AM4 screws do match the BSW 32G 5/32 thread pitch. The pitch of 32TPI is 0.79375mm which is as near as dammit 0.8mm. The metric threads are 60 degrees and the BSW threads are 55 degrees, which is close enough to take the tension.. However, 5/32" is almost 4mm and will not fit the AM4 backplate.

I will use the Noctua backplate with the springs from the original screws, but with longer, cap-headed machine screws.

 

[lorry]

I have been trying to fit an AM4 board and Ryzen 5 into a fanless, heat-pipe cooled chassis. Having solved the problem of the changes to the screw-hole placings between AM3 and AM4, I hit the problem that the original screws were the wrong thread. All I needed to do was obtain longer screws with the correct thread and use the original tension springs. (BTW, the stock cooler that came with the Ryzen 5 uses captive screws with springs secured by circlips which screw into the backplate, rather than one of the other two alternatives, one of which clips over the plastic brackets.)

The following is what I have found from my measurements. The original screws are 3mm and have a pitch of 0.5mm. This appears to be a standard size as my supply of machine screws fits the original board fittings.

The AM4 screws are 3.5mm and have a pitch of 0.8mm.

3.5mm is the standard screw to fit wall sockets in the UK, so they will be easy to source, won't they? Unfortunately, not. The standard for 3.5mm screws is a pitch of 0.6mm.

The AM4 screws do match the BSW 32G 5/32 thread pitch. The pitch of 32TPI is 0.79375mm which is as near as dammit 0.8mm. The metric threads are 60 degrees and the BSW threads are 55 degrees, which is close enough to take the tension.. However, 5/32" is almost 4mm and will not fit the AM4 backplate.

I will use the Noctua backplate with the springs from the original screws, but with longer, cap-headed machine screws.

I found this site, which seems to have as complete a range as anything else I've found, plus some

Accuracy. Delivered. | 500,000+ Components - Accu

Buy Precision Fasteners, Lead Screws, Captive Screws, Nuts, Washers, Hardware & Mechanical Components At Accu.co.uk.

www.accu.co.uk

 

[Jazzer]

OK, that site has gone into my Bookmarks. Thanks.

I just had to look. They offer a great range of 3.5mm cap-headed screws, all to DIN 912.

I looked up the DIN 912 standard to find out the thread pitch and it cited the pitch for 3 mm as 0.5 mm which is just what the AM3 socket uses. Then I looked up the 3.5 mm thread pitch, only to find that 3.5 mm is not even in the DIN 912 standard. So, the defacto standard for the M3.5 screw is 0.6 mm, but AMD are quite entitled to make it any pitch they like. Doh!

I note that the DIN 912 pitch for M4 is 0.7 mm, so they are being a little naughty for making their M3.5 screws 0.8 mm pitch.

I hope your description of the Noctua AM4 back-plate is close: I have machined up some 3 mm-threaded 'top hat' inserts that slip into the back of the Noctua back-plate holes and extend through the motherboard to the same distance that the stock, back-plate studs extend. I can, now, use the original cooler thumbscrews, screwed into the 'top hat' inserts. Just to be sure, I have ordered long, expensive, cap-headed 3 mm screws in case the top hat insert solution does not work.

 

[lorry]

OK, that site has gone into my Bookmarks. Thanks.

I just had to look. They offer a great range of 3.5mm cap-headed screws, all to DIN 912.

I looked up the DIN 912 standard to find out the thread pitch and it cited the pitch for 3 mm as 0.5 mm which is just what the AM3 socket uses. Then I looked up the 3.5 mm thread pitch, only to find that 3.5 mm is not even in the DIN 912 standard. So, the defacto standard for the M3.5 screw is 0.6 mm, but AMD are quite entitled to make it any pitch they like. Doh!

I note that the DIN 912 pitch for M4 is 0.7 mm, so they are being a little naughty for making their M3.5 screws 0.8 mm pitch.

I hope your description of the Noctua AM4 back-plate is close: I have machined up some 3 mm-threaded 'top hat' inserts that slip into the back of the Noctua back-plate holes and extend through the motherboard to the same distance that the stock, back-plate studs extend. I can, now, use the original cooler thumbscrews, screwed into the 'top hat' inserts. Just to be sure, I have ordered long, expensive, cap-headed 3 mm screws in case the top hat insert solution does not work.

For me it fitted the Gigabyte X470 Gaming 7 wifi perfectly.
My problem was that I found it fiddly as hell to get it all together (i have disabilities, so I am at a disadvantage for anything awkward to fit).
I did a dry run and it fitted just fine with some titanium bolts that I found on eBay, but they were 5mm too short.
Here's a pic of the dry run with 3 of the 4 bolts in place

https://imgur.com/WR0M4eY

 

[Jazzer]

For me it fitted the Gigabyte X470 Gaming 7 wifi perfectly.
My problem was that I found it fiddly as hell to get it all together (i have disabilities, so I am at a disadvantage for anything awkward to fit).
I did a dry run and it fitted just fine with some titanium bolts that I found on eBay, but they were 5mm too short.
Here's a pic of the dry run with 3 of the 4 bolts in place

https://imgur.com/WR0M4eY

I have been giving this a bit of thought. I suggest you try fitting bolts through the back-plate and screwing on the nuts, but leaving enough space between the nuts and the backplate to put tiny dots of superglue on the outside edge of the nuts. Place the back-plate with the nuts uppermost and resting against the back-plate until the superglue sets.

With luck, you will be able to gently refit back-plate, nuts and bolts to the motherboard without breaking the superglue bond.

If you want to change things around, in the future, you should be able to easily detach the nuts from the back-plate and scrape the superglue, off of all surfaces.

 

[lorry]

I have been giving this a bit of thought. I suggest you try fitting bolts through the back-plate and screwing on the nuts, but leaving enough space between the nuts and the backplate to put tiny dots of superglue on the outside edge of the nuts. Place the back-plate with the nuts uppermost and resting against the back-plate until the superglue sets.

With luck, you will be able to gently refit back-plate, nuts and bolts to the motherboard without breaking the superglue bond.

If you want to change things around, in the future, you should be able to easily detach the nuts from the back-plate and scrape the superglue, off of all surfaces.

The trouble with that is that there is Very little 'wriggle-room' with this particular motherboard, you can see in this picture that the bolts are right on the extreme of the mounting slots on the block.
I have no idea if this is true with other MBs, or if it is only true for x470 or Just my board?

https://imgur.com/fL8VXZw

What would be better would be to find out what double-sided pads they use for the original backplate and then just using that.
When things improve C19-wise there is a local precision engineering firm that could likely weld the buts in-situ I'm sure
Or of course have @Optimus Water Cooling come up with an updated mounting design, which is what they said they will do for the future (obviously that isn't possible currently).

 

[Jazzer]

The trouble with that is that there is Very little 'wriggle-room' with this particular motherboard, you can see in this picture that the bolts are right on the extreme of the mounting slots on the block.
I have no idea if this is true with other MBs, or if it is only true for x470 or Just my board?

https://imgur.com/fL8VXZw

What would be better would be to find out what double-sided pads they use for the original backplate and then just using that.
When things improve C19-wise there is a local precision engineering firm that could likely weld the buts in-situ I'm sure
Or of course have @Optimus Water Cooling come up with an updated mounting design, which is what they said they will do for the future (obviously that isn't possible currently).

Ah, I misinterpreted your photo. I'd assumed you would be putting the nuts under the motherboard. I was proposing doing the gluing with just the back-plate, nuts and bolts. That gives you a back-plate with 'captive' nuts that can then be offered up to the motherboard and cooler for final assembly. The bolts can be dropped through the cooler slots and will rest on the threads of the nuts. If you have a suitable 'nut-spinner' (a screwdriver, but with a socket on the end) or a 1/4" socket set, tightening the bolts would be relatively easy.

If you are going to get some engineering done, don't think of welding: get someone to turn four nuts in the shape of a top hat that extends into the holes in the back-plate and motherboard. Here are the ones I turned, drilled and tapped out of brass rod. One of the original thumbscrews is shown screwed into the 'top-hat' insert. If you have a friend with access to a metal working lathe, they could machine them up in a couple of hours.

 

[lorry]

Ah, I misinterpreted your photo. I'd assumed you would be putting the nuts under the motherboard. I was proposing doing the gluing with just the back-plate, nuts and bolts. That gives you a back-plate with 'captive' nuts that can then be offered up to the motherboard and cooler for final assembly. The bolts can be dropped through the cooler slots and will rest on the threads of the nuts. If you have a suitable 'nut-spinner' (a screwdriver, but with a socket on the end) or a 1/4" socket set, tightening the bolts would be relatively easy.

If you are going to get some engineering done, don't think of welding: get someone to turn four nuts in the shape of a top hat that extends into the holes in the back-plate and motherboard. Here are the ones I turned, drilled and tapped out of brass rod. One of the original thumbscrews is shown screwed into the 'top-hat' insert. If you have a friend with access to a metal working lathe, they could machine them up in a couple of hours.
View attachment 158583

yes That's what I would prefer, hand't thought of trying that way must admit, food for thought for when I upgrade the MB a bit down the line.
Thanks, that is Def worth looking into.