EEVblog Electronics Community Forum
Electronics => Beginners => Topic started by: ammjy on September 01, 2020, 05:15:01 am
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Hello !
I need a screwdriver for M2.5 size screw. but I can not figure out that which PH number I need to buy.
could you give some advise ?
Thank you !
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Impossible to tell it might even be pozidrive. Pick up an affordable set of Jewelers screwdrivers then if its a really critical 'must not mar' screw that's in tight, buy a really good fairly long screwdriver of whichever size fits best, with a good sized grip on it, slightly moisten the tip and dip it in a vial of 1000 grit diamond powder to minimize the risk it will slip in the head and FUBAR it.
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Thread size doesn't determine the head size. I just grabbed a couple of random M2.5 and M2 screws I had, and both of them seemed to be PH 0. So for Phillips screws that is probably what you're looking for.
Like Ian said, a set of small screwdrivers is nice to have.
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About a minute on Google obtained this link:
http://fastener-express.com/fastener-technical/Metmachflathd.pdf (http://fastener-express.com/fastener-technical/Metmachflathd.pdf)
for Philllips screwdrivers for metric screws
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Most likely PH0 or PZ0
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M2.5 is quite large for PH0, more likely should be PH1. PZ is rarely used with screws below M3.
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The reference I quoted recommends PH1 for both M2.5 and M3.
PH0 for M2 and M1.6.
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BTW if you wonder which screwdriver you should buy for a particular screw, you better should buy screwdriver set. Since having to buy a new screwdriver on each occasion you already need it is quite lame. One of the best affordable small screwdriver sets is from Xiaomi (made by Wiha). https://www.banggood.com/XIAOMI-Mijia-24-in-1-Multi-purpose-Precision-Screwdriver-Set-Aluminium-S2-Steel-Repair-Tools-p-1187158.html?cur_warehouse=CN (https://www.banggood.com/XIAOMI-Mijia-24-in-1-Multi-purpose-Precision-Screwdriver-Set-Aluminium-S2-Steel-Repair-Tools-p-1187158.html?cur_warehouse=CN) Be aware of counterfeits/clones since they are junk.
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One of the best affordable small screwdriver sets is from Xiaomi (made by Wiha).
Now that's a first, buying Wiha tools with a Chinese co-branding from China... Seems to be a genuine collaboration, where Wiha presumably makes the bits (or gives their blessing and name for bits made by Xiaomi?), and Xiaomi makes the handle and package? Thank you for the pointer!
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This can be a lot trickier than you might think at first look. First off there are at least 3 types of Phillips like screw heads. The American Phillips are very common in the USA (defacto standard), Japan had at one time a JIS standard for a Philips like head and then there is an ISO standard. Most of Japan has moved to the ISO Phillips, but you still need a different driver to work correctly on the JIS standard "Phillips". So you need to know what sort of Phillips type head you will be working with.
I have to agree with another post here, buying just one screw driver doesn't make a lot of sense. If you has a set of Phillips drivers from #0 to #4 you wouldn't even have a question here.
Hello !
I need a screwdriver for M2.5 size screw. but I can not figure out that which PH number I need to buy.
could you give some advise ?
Thank you !
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I use such a one NEO №.1x75mm (it works ok from 2.0 mm to 4.0 mm):
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I use hundreds of M2.5, M3 and M4 screws. I have yet to see an M4 with a PH1 head. I have seen others mistakenly use a PH1 driver on PH2 heads.
My driver of choice for PH1 is the Wiha 96110,
https://www.digikey.at/product-detail/en/wiha/96110/96110-ND/512122 (https://www.digikey.at/product-detail/en/wiha/96110/96110-ND/512122)
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Yes, my reference suggests PH2 for M4 and M5 screw heads.
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I use such a one NEO №.1x75mm (it works ok from 2.0 mm to 4.0 mm):
Your screwdriver belongs to a trash bin since it's flanges are damaged.
(it works ok from 2.0 mm to 4.0 mm)
And this is the most likely reason why it's damaged. You mismatched screw and screwdriver sizes which results in damaging both.
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I use such a one NEO №.1x75mm (it works ok from 2.0 mm to 4.0 mm):
Your screwdriver belongs to a trash bin since it's flanges are damaged.
Trash bin is right!!. A worn or poorly designed Phillips drivers will damage screw in a blink of an eye. This is why commercial users, in construction for example, use drivers with replaceable bits or blades. For manual use I found that Wera makes one of the better Phillips tips.
(it works ok from 2.0 mm to 4.0 mm)
And this is the most likely reason why it's damaged. You mismatched screw and screwdriver sizes which results in damaging both.
This is why it really pays to have a large collection of Phillips drivers. The other thing that damages Phillips screws is having drivers that are too short not allowing for the straightest possible alignment of the driver.
Screw drivers are a situation where it really pays to buy quality. Avoid the Walmart specials, anything labeled Sears or Craftsman, almost anything from Harbor Freight and cheap auto parts stores. It rather surprised me that auto parts stores would sell cheap tools but I literally had one purchased brand new spin the handle on the shaft. I forgot what that brand was but it wasn't anything yet mentioned. The point is there is a lot of junk screw drivers being sold these days. Sadly good ones are not that much more and can usually be purchased one at a time to spread the hit out.
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Worn out PH1 drivers can be repurposed into Ph2 drivers by grinding the point flat so that it sits deeper into the PH2 head.
My old Wiha 96110 drivers modified this way are very useful for rapidly spinning M3 screws because of the small diameter handle.
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I use such a one NEO №.1x75mm (it works ok from 2.0 mm to 4.0 mm):
Your screwdriver belongs to a trash bin since it's flanges are damaged.
(it works ok from 2.0 mm to 4.0 mm)
And this is the most likely reason why it's damaged. You mismatched screw and screwdriver sizes which results in damaging both.
No, possibly that seemed from photo but my screwdriver is quite new (wasn't used with a much pressure), and I have several other sizes so I use them properly. And it is good quality. So it is not worn yet.
To tighten M4 and larger (if there is a need) I use larger ones, but most times this No1 works ok for me.
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but most times this No1 works ok for me.
There is no "works OK". It either matches the size or not. Unless some wery crappy out of spec screws are used. And screwdriver is certainly worn because flanges already became concave instead of of flat.
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Trash bin is right!!. A worn or poorly designed Phillips drivers will damage screw in a blink of an eye. This is why commercial users, in construction for example, use drivers with replaceable bits or blades. For manual use I found that Wera makes one of the better Phillips tips.
Interesting point about being able to replace just the bits. Never thought of that, as for construction use the main thing would seem to be the ability to use power drivers. I notice that electricians use normal screwdrivers, not bitted ones, and seemingly they would have the same issue with tips wearing.
I have a full set of Wera precision screwdrivers that are nice (I have lots of Wera tools in general, and a smattering of Wiha), but I find myself more often using the cheap-ish bitted set I have, available under multiple chinese brand names on amazon. ~$22 for 22 different size bits. I bought 'nanch' but there are other names which are obviously the same set. It's not junk quality but it's not Wera quality either. I only just this moment figured out what the pull-back spring collar at the bit end is for. I thought it was some pointless decorative thing. Turns out it's for a built-in telescoping function.
This Xiaomi / Wiha set is very interesting! I went ahead and ordered it. I understand much Wiha stuff is made in Vietnam, at least their bits. I am wary that this is like Snap-On "blue point" products (made in china). Why in the world would a toolmaker with a reputation like Wiha do a co-branding with Chinese company? I bought a set anyway.
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Bits are not as universal and convenient as a solid screwdriver. Bits are wider in diameter and a bit loosy.
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Got the Xiaomi set. Very nice, although not sure I'd buy again. It's very slightly different than the product photos. Rather than just the logo on the outer case, it has the logo and 'Wiha'. The case is unnecessarily spring loaded to eject the tray. That's just asking to break. A magnet block in the tray to hold the bits in place is very nice. I like this better than plastic nubs. The engraving on the bits is very deep and very easily read. That alone speaks to the high quality. The bits themselves seem quite good, but unlike my Wera set, have no serrations for better screw holding. I've not gaged them but the bits seem very precise. The overall fit and finish of the set is of a very high standard.
Made in China, and intended only for Chinese market as none of the labels or documentation card have other than Chinese language. With that context, this co-branding makes sense market-wise. The bit type and size engravings are English, but I would expect this universally anyway. The Torx bits have the entire word 'Torx' engraved. Never seen that before.
Forum is broken and I can't post additional pictures. Probably size limitation where the error isn't reported correctly.
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Rather than just the logo on the outer case, it has the logo and 'Wiha'.
It always was like that. Dunno why you think it should be otherwise.
The case is unnecessarily spring loaded to eject the tray. That's just asking to break.
Cannot agree with you. It's pretty convenient. And how it should be held otherwise?
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Rather than just the logo on the outer case, it has the logo and 'Wiha'.
It always was like that. Dunno why you think it should be otherwise.
The product photo at banggood, where I bought it, has a different imprint. I expect the product photo to be what I actually get.
The case is unnecessarily spring loaded to eject the tray. That's just asking to break.
Cannot agree with you. It's pretty convenient. And how it should be held otherwise?
simple snap/friction fitting (small nubs that fit into a detent). push from either side to slide out the inner tray. or, a clear plastic cover that slides off. or, given the use of magnets already, a hinged lid that snaps shut via magnet. there are many choices. the spring eject doesn't inspire confidence of durability to me.
on second thought, i do not like the magnet retention of the bits into the tray. too easy to overturn and have them all fall out, as the magnet is not strong at all. I have learned over the years that you can and will drop every tool.