Can someone here visually identify the size of these screws, or help me determine what size I need?
Posted 12 February 2019 - 06:28 PM
I have a Sager NP9876/Clevo P870KM1-G (Clevo is a famous Taiwan manufacturer, Sager is their main distribution arm in the US, they merely rebrand the hardware, in 99.9% of cases they are 100% identical except in name). I am having trouble determining the exact size of the exterior case screws, of which there are 9. In 2017/2018 I disassembled it to install an SSD/HDD, it seems I stripped several screws when putting them back in (too tight). So when I took it apart several days ago to install another SSD and do some cleaning, I had a very difficult time removing the screws, even with the aid of a tiny magnet. Once the screws are loose it is still very difficult to remove the case with fingers alone, it is a very tight fit, pry tools make it much easier. I spent nearly an hour just removing the screws and bottom cover.
Now I need to order replacement screws, but I am not sure what size I need. Some sellers like XoticPC want over $40 just for these model specific screws, but that is a ripoff, I am sure they are a generic industry-standard size.
I had recently posted on XoticPC forum about this (https://www.xoticpcf...o-p870km1-g-use), but it has gotten very few views and no answer. That is the company I bought the laptop from.
I am linking to a pic I uploaded on Imgur (too large to upload here), albeit a bit blurry, perhaps someone can visually identify the size:
If that doesnt help then maybe someone can dig up some dirt elsewhere. I tried searching Google for several hours but it seems noone lists the dimensions. There is nothing on the outer casing showing their size, or on the inside of the bottom case once it is removed. I also tried looking on the outer edges of the mainboard where the screwholes are, but no size listed there either (my old ASUS ROG had clear markings here indicating the size, I figured Sager would do the same, nope). I also checked the owners manual and the size isnt listed there either.
Posted 12 February 2019 - 08:27 PM
You are using - besides strange tools - also strange math.
The out of focus and blurred photo you posted is about 8 (eight) screws on a saucer.
If there were 9 (nine) in total and you find that 2 (two) are missing how many have you left?
There is no way anybody can tell you the size of a screw from a photo (even if it wasn't so terrible).
If your laptop is similar to the one in this video, yes, the total seems like 9:
If you overtightened them it is possible that the actual threads on the nut/screwholes are ruined besides - possibly - the ones on the screws (and or the screw head), if this is the case you need to find a suitable threading tool (and it is not easy-peasy if you are not familiar with the matter to re-thread such a small hole and/or fix it).
If the threads on the nut is damaged, as soon as you will insert new screws they will likely be damaged like the old ones.
You need anyway a caliper and a
thread counter thread pitch gauge to measure and identify the exact size of those screws (and then start searching for them, usually they are not "standard").
Don't you know someone that runs a repair shop or something similar (a car repair shop will normally have a caliper and a thread counter and know how to measure a screw)?
Typically (but cannot say on your specific laptop) they are 2.5 mm in diameter and 6/8/10 or 12 mm in length.
Or you could "risk" a few bucks for a "generic" kit like (example):
Posted 13 February 2019 - 05:16 AM
My math does *seem* wrong but it isn't. Yes, 9-2=7 obviously, there was no need for you to write out the numbers in addition to the actual number. I'm no idiot, didn't grow up in a 3rd (third) world country with no education. And did attend university for a short time, but found it boring, and difficult to get along with/associate with others. So where did the 8th screw come from? Well, while I was cleaning I noticed a loose screw just sitting on the mobo, the others were already in the bowl. So I assumed it must have been lost from last year, it fit the case holes perfectly and matched the size of the others. The total doesnt *seem* like 9, it *is* 9, a complete idiot can count screwholes vs number of screws present.
I checked the threading on the screws, all 8 seemed fine/not stripped. But on several the heads of the screws are damaged. I took one of the other good screws and subbed it into the hole where a bad screw was, no issue inserting or removing. So I dont think the actual holes are damaged.
Not sure what you mean by caliper, is it similar to the pliers some craftsmen use, the kind you can buy in a hardware store? Nor am I familiar with a thread counter.
Thanks for letting me know that screws are usually measured in millimeters, I can probably just use a ruler/tape measure to determine the screw length/head size. The sizes you listed seem pretty standard to me, they are standard length/width and usually have a Phillips head. And since multiple PC brands use the sizes you listed then I consider that standard. It's not like we're dealing with Apple screws (knockoffs of Torx), and Pentalobe hexkey screwdrivers.
I don't know anyone that runs an auto shop, I only ride my bike and walk to get places, sometimes bus/train. I can't drive a vehicle to save my life, never learned. So I have no reason to visit an auto shop with laptop screws. I once asked a welder if he could could meld aluminum to steel, for a personal project and I was willing to pay his asking price, he said it can't be done easily, I thought for sure it could. In others words, it's not worth their time to look at even if remotely possible. No sane business owner will waste time/money/effort on something unlikely to work.
Your link is good but it is missing some of the sizes you listed, this one covers all of them:
https://www.amazon.c...op screws sager
I also noted that you didn't mention odd sizes like 9 (except 2.5 which has an odd number, but is an even amount, i.e. 2.50, i.e. 2 1/2, i.e. two and one half, etc). Why?
I don't need them all but I guess you can never have enough spare screws. Just have to see if they sell them in something less than a 300pc set, 100 is fine, as long as all screws have at least 2 (as a backup).
In the future you can talk to me not as a kindergarten/grade school student, but as a full adult with above-average intelligence, capable of understanding most of the words that you would expect in to be in the vocabulary of someone that grew up in a country with good educational organizations/regulations. And there is usually no need to nitpick over insignificant details like screw count, which don't contribute to the overall solution of the topic. Who cares if I only had 7 vs 8?! It really doesn't fucking matter, now does it? And you do not need to oversimplify things as if you are talking to a small child. Maybe clarification on some things, but nothing more.
I have lately been making an effort to not be such a prick in this community or online, due to new spiritual practices. But the fact remains that I can be mentally and emotionally unstable, and socially volatile. I will only need some nitpicking or other slight that might send me back over the edge into prickhood. And make no mistake, my mental issues do not in any way dilute my intelligence or capacity to learn advanced topics. What I have is an unusual mix of antisociality, schizoid/schizophrenic, ADD/ADHD, bipolarity, something like high functioning Aspergers/autism, and supposed math learning disabled. And then there are other times when I function fine, it's a drift in/out thing.In other words, unpredictable. Let's just say I'm not someone you want to put in command of the nuke codes, Trump has nothing on me there.
Posted 13 February 2019 - 07:42 AM
Posted 13 February 2019 - 09:18 AM
For what I know, only threaded length is important, since only the threaded part defines their main functionalities...
Posted 13 February 2019 - 10:53 AM
A ruler is simply not good enough, you need a caliper:
More exactly a Vernier caliper:
I used the wrong English term, I meant thread pitch gauge, one of these:
No, they are surely not 4 mm in diameter, they will be either 2.5 mm or (maybe) 3 mm.
Here is how the dimensions of a screw are measured (and where you can order a limited amount of screws for a few bucks, once you have identified them):
Very likely your screws are of this kind:
But the "penny test" is not "exact".
Posted 13 February 2019 - 07:27 PM
I think you must be measuring the head of the screw to get M4 – you should be measuring the threads to get the diameter of the screw. M2.5 is the most common diameter for case screws. Some of the small laptops use M2 or M1.6.
For the length 5 and 8 are the most common lengths so if you measured 8mm for the length that would be one of the most common lengths.
This screw is an M2.5x8 with a 4mm head:
That explains alot. But when measuring length, are you supposed to include the head? Because if so, I think the size I need would be closer to M2.5x6, not 8.
I'm definitely still going to consider getting some of the other tools mentioned in this thread, they may prove useful later. But I think the rep is probably dead-on for the size.
Posted 13 February 2019 - 07:30 PM
That explains alot. But when measuring length, are you supposed to include the head?
Read (ALREADY given link) how a screw is measured (Compaq/HP method is different and wrong):
I am posting the image, should you have issues getting to the given page:
We give both the overall length and the thread length. The clickable size given in the menu on the left is the thread length in the case of pan head and oem wafer head but the overall length for the flat head screws. Some laptop manufacturers (ie HP & Compaq) measure overall length but some measure from underneath the head like you would a regular pan head. So be aware of this if you are using sizes given in a service manual.
Yours are likely "oem wafer head", BUT the one you linked to, is an "extra thin head", from what can be seen from the photo you posted the head seem "chunkier", i.e. like this one:
(though it should make not a difference between 0.71 and 0.77 head thickness), exact length (of the threaded part) is more important.
Posted 13 February 2019 - 07:42 PM
Posted 13 February 2019 - 07:57 PM
@Wonko: Well, I had initially measured the length from the bottom of the screw to the top of the head (before reading the link you gave), and my total was roughly 8. So, measuring again without the head, it appears to be 6. So, M2.5x6. So either I'm wrong again and the rep is correct, or my new calculation is the right size. Problem is, the M2.5x6 wafer head screws they list look alot smaller than what I have.
Well, even if not exact, if you do a penny test, making a photo that is actually focused and not blurred, you can still compare it to the images provided by the given site(s).
Still if the total length (including head) is around 8 mm, the head must not be too thin if the thread is 6 mm.
They could be 7 mm with head thickness 0.80:
Calipers have been invented exactly to make this kind of measure, really *any* mechanical repair shop (bycicles, motorcycles, cars, etc,) will have a caliper, can't you ask anyone to measure one of the screws exactly?
Since a penny is 1.52 mm in thickness
so if you stack four of them you have almost exactly 6 mm (6.08) mm and with five of them you have almost exactly 7.6 mm.
Is the 4 penny stack taller or shorter than the thread (excluding the head)?
Is the 5 penny stack taller or shorter than the thread (excluding the head)?
Posted 14 February 2019 - 03:58 AM
I went into a local Home Depot hardware store and mentioned a vernier caliper and why I needed it, several of the employees at the service desk knew exactly what it is and produced one nearly identical to the one @Wonko posted. Cost, about $15. I dont know how to use it but I'll figure it out somehow.
Posted 14 February 2019 - 03:59 PM
Generally speaking, it is a good thing that the screws used on a laptop (please read as something that is subject to vibrations and - hopefully not hard - shocks and crashes) have the Loctite-like thread locking substance.
The difference among the various M2.5x8 screws that we have seen is as said marginal - as long as the diameter of the head is correct, having then 0.71, 0.77 or 0.80 mm thick won't make a difference.
About the Vernier caliper you got is that a "traditional" one or one of the newer "digital" ones? (digital ones are "direct read", traditional ones need a little bit of attention/experience)
Is it in mm (metric) or imperial (inches)? (you might need to perform a conversion between (decimal fractions) inches and mm)
If you check these:
The first one shows how to use one (but is IMHO not very clear on how to actually read the scale), the second is very clear about how to read the scale.
To measure the diameter of the screw and of the head you use the jaws (for measuring outer dimensions), to measure the length of the screw (threaded part) you use the "stem for measuring depth" OR the "jaws for inner dimensions", to measure the whole length (head included) of the screw you use again the jaws (for measuring outer dimensions), check this video:
Posted 14 February 2019 - 11:17 PM
Posted 15 February 2019 - 08:44 AM
@Wonko: The one I bought requires you to measure/read by hand. They also had digital vernier calipers in stock for around $10 more. But the rep was an older guy, looked like he was maybe mid 50s or early 60s, he suggested to get the non-digital and learn to use it, then switch to digital later. He also made some remarks about younger people being too reliant on technology instead of learning to do things by hand/manually. He struck me as the type of guy that would rather cut boards with a handsaw instead of an electric Skilsaw. Or use a hammer to drive nails instead of a nailgun.
Well, you were advised correctly.
From experience, and being myself "maybe mid 50s or early 60s" I can tell you that the "manual" ones are actually a tad bit more accurate (not that it is needed in common measurements), i.e. typically you can have reliable 5/100 of a mm measurements, while the newer digital ones, particularly the ones that you can buy for a few bucks, tend to display millimeters point tens followed by a "semi-random" number.
That is however not the actual issue with them, the real one is that when you will need it again (like in a few months from now) due to Murphy's Law the small button battery will be exhausted (or its contacts will be oxidized) and it won't work until you clean the contacts, replace the battery, etc. making what could have been a three to five second task a several minutes one (and provided you have a spare battery, usually you don't and you start disassembling random small battery powered devices to find one, or need to get to a shop to buy one, making it a several tens of minutes task)
I have a couple calipers that were my grandfathers', thus manufactured before World War II that still look (and work) as new.
Compare with legacy as defined here:
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