What the heck kind of terminal screw is this?! - Page 1
Forum section: electronics / beginners

author: JayMan07
author_rank: Regular Contributor
timestamp: February 25, 2018, 02:34:27 pm
content: At work I have to tighten 14 awg wires into these terminal block screws...What the h*%$ kinda screw is that. If you look closely, it's not truly phillips, JIS, or flathead even though you can force all of those to work.The circuit board is inside of a metal housing and suspended off the back. In order to tighten the terminals correctly you have to put so much downward pressure on the screws (to keep your screwdriver from caming out) that it bends the circuit board like 3/16". There is no support under the terminalsMy co-worker almost lost his mind the other day trying to tighten them. I ground the points down on both of our phillips screwdrivers and it helped, but it's still pretty frustrating.I have several really nice kleins made for terminals, but like I said none of them really work that well. What are you guys using to tighten these?

author: DimitriP
author_rank: Super Contributor
timestamp: February 25, 2018, 02:52:36 pm
content: You need one of these:https://www.wihatools.com/insulated-tools/screwdrivers/terminal-block/insulated-combination-terminal-block-xeno-screwdrivers

author: JayMan07
author_rank: Regular Contributor
timestamp: February 25, 2018, 03:29:08 pm
content: Ok that does look right. Would the number 1 size be the right size for those terminal bocks?

author: SeanB
author_rank: Super Contributor
timestamp: February 25, 2018, 03:53:28 pm
content: JIS standard screws, so you actually need a Pozidrive as the next alternative to the JIS screwdriver for them. No0 Pozi works well, though I often simply use a small flat screwdriver instead, as that is something that works perfectly on these. trick is getting a screwdriver with a parallel blade that is the width of the screw housing, or if it is not one slightly wider and grind it down slightly to make it a nice fit. I keep a screwdriver for those in my tool kit for networking, as those screws are common there for power on PCB assemblies. Coincidentally I also ground the profile of that screwdriver ( marked with some tenacious yellow tape on the shaft to identify it) to the right profile to handle Quante punch down block termination, as the correct Quante punchdown tool is both insanely expensive and also just as fiddly to use, and I only have to deal with them every so often so the screwdriver option works just as well. Started out as a Wera screwdriver and then had a trip to the grinder to get it right. Quante was a very short lived solution from the local telecoms monopoly, thankfully they only had it for around 2 years and I unfortunately had a lot installed, so have to deal with it. I prefer Krone punch down blocks, and have all the tooling for them as well as it is cheap, plus they are as reliable as those nasty Quante gel filled units. I do have one of the tap in test plugs though, just in case I need it on Quante, but the Krone I have the full set of insert and bridge blocks.

author: JayMan07
author_rank: Regular Contributor
timestamp: February 25, 2018, 10:27:42 pm
content: I did some digging and I believe the Wiha Xeno #1 will not fit in those terminal blocks. I currently use a Phillips #0 on them. Since the #1 is the smallest that Wiha makes I may get it and grind it down to fit. I would like to hear if anyone else has any suggestions though.

author: Cerebus
author_rank: Super Contributor
timestamp: February 25, 2018, 11:43:53 pm
content: I've always had good results on those with a either a No. 1 Pozidrive or the classic parallel bladed small electrician's terminal screwdriver (mine's 3.5mm).BTW, if you use a Phillips driver on a Pozidrive head it will cam out and simultaneously chew up the head, almost 100% of the time, with the slightest provocation. The combination of the two is almost perfectly un-designed to do exactly that.The Phillips was designed with tapered, slightly hollow ground, sides to cam out safely if it was over-torqued, the Posidrive was designed with square sides to grip harder as it was torqued more, and somewhere at the intersection of the two is a whole big heap of 'nope!' as the Phillips driver only engages on a fine edge rather than on the whole face of the Pozidrive head.If you look at those terminals they have the straight sides and square bottom of a Pozidrive, with a slot added on top for good measure. If you look carefully you can see the vestiges of the extra ribs at 45 degrees that are a feature of Pozidrive. I don't think those are JIS precisely because of the 45 degree features, which are absent on JIS.

author: langwadt
author_rank: Super Contributor
timestamp: February 25, 2018, 11:55:48 pm
content: Quote from: JayMan07 on February 25, 2018, 02:34:27 pmit made so sparky can stick what ever sharpened nail he calls a screw driver and last used as a pry bar in there

author: JayMan07
author_rank: Regular Contributor
timestamp: February 26, 2018, 02:06:14 am
content: Quote from: Cerebus on February 25, 2018, 11:43:53 pmThank you! I just tried a Pozidrive on it and it really grips well. Looking closely at it I can see exactly what you mean by the pozidrive having square sides vs a phillips with tapered sides. That small detail does seem to make a huge difference.

author: IanB
author_rank: Super Contributor
timestamp: February 26, 2018, 02:21:07 am
content: They look like standard electrical terminal screws, as found in all mains outlets and terminal blocks. A standard electrician's screwdriver of the appropriate size will fit them perfectly.(14 AWG suggests they are big. There may be different sizes of these screw heads. The picture gives no clear indication of scale.)

author: IanB
author_rank: Super Contributor
timestamp: February 26, 2018, 02:31:06 am
content: Here's an example of the bit designed to fit those screws:(It's a USA electrical terminal screw bit, for want of a better description.)

author: ez24
author_rank: Super Contributor
timestamp: February 26, 2018, 07:34:59 am
content: Ordered thishttps://www.aliexpress.com/item/UXCELL-Booher-Authorized-75Mm-Bar-Length-Pz0-Pozidriv-Screwdriver-Repairing-Tool/32810809694.html

author: paulca
author_rank: Super Contributor
timestamp: February 26, 2018, 08:26:32 am
content: I thought these were just so you could use either a flat terminal screw driver or a generic "cross" head.

author: ez24
author_rank: Super Contributor
timestamp: February 26, 2018, 08:42:50 am
content: Quote from: paulca on February 26, 2018, 08:26:32 amNope

author: JayMan07
author_rank: Regular Contributor
timestamp: February 26, 2018, 11:27:49 am
content: Quote from: IanB on February 26, 2018, 02:21:07 amYes I'm familiar with those screwdrivers and the kind of screws on outlets. These are smaller maybe like a head diameter of 3.75mm. Also if you look closely the pattern is different.Update: After messing around with it a lot it seems a pozi #1 and my klein with the pint ground off are about equal in their ability to grip these screws. It was cool to see the pozi drive work better than a regular phillips but I'm still kind of back where I started.What was so wrong with a regular flat head terminal screw that they had to change it to this idiotic design.

author: ciccio
author_rank: Frequent Contributor
timestamp: February 26, 2018, 02:37:00 pm
content: Quote from: IanB on February 26, 2018, 02:31:06 amPlease add a link or a manufacturer's name and/or model.I've googled for it but no results.Best regards

author: tautech
author_rank: Super Contributor
timestamp: February 26, 2018, 02:50:43 pm
content: Combo tip driver.https://express.ecsnz.com/en/combo-tip-driver-pzfl2Less push force is required for equivalent torque and therefore less strain on electrical HW mountings.

author: Monkeh
author_rank: Super Contributor
timestamp: February 26, 2018, 02:56:08 pm
content: Oh, yay, yet another screwdriver...Hello, world. Torx. We've had it a while.

author: JayMan07
author_rank: Regular Contributor
timestamp: February 26, 2018, 09:57:49 pm
content: Quote from: ciccio on February 26, 2018, 02:37:00 pmIt's a milwakee ECX bit...ok for outlets but won't work on these screws.

author: JayMan07
author_rank: Regular Contributor
timestamp: February 26, 2018, 09:59:44 pm
content: Quote from: Monkeh on February 26, 2018, 02:56:08 pmI know I can't possibly imagine why anyone would design a fastener like the one I posted a picture ofThere are so many other good options

author: ez24
author_rank: Super Contributor
timestamp: February 26, 2018, 10:06:12 pm
content: The pic of a meter back is what I need to turn. I have a big selection of all kinds of small screwdrivers, flat, cross, and Torx. The only way to turn them so far is using a flat or a pair of needle nose pliers. Both methods are hard to use.I now am waiting for my Pozidriv to arrive.Screwdriver:https://www.aliexpress.com/item/UXCELL-Booher-Authorized-75Mm-Bar-Length-Pz0-Pozidriv-Screwdriver-Repairing-Tool/32810809694.htmlThe only thing I do not know is the size, so I just ordered this because I see there is a pz00 in the sethttps://www.aliexpress.com/item/16pcs-percision-screwdriver-set-min-computer-screwdriever-Screwdriver-slotted-PH00-PH0-PH1-T6-T7-T8-T9/32536044000.htmlFound a 000 here (my guess this is what I need)https://www.aliexpress.com/item/Flexsteel-Good-Quality-10PCS-CR-V-Precision-Screwdriver-Bit-Set-Including-PH000-PH00-J0-J1-J00/32746275268.htmlLooking through this ad, it says the 000 is 0.8mm and then shows a picture of Torx and this one. The Torx has 6 wings and the 000 has 5. But 0.8 is really small so I am not sure now but I ordered different sets with different sizes to be sure.Meter:https://www.aliexpress.com/item/DC-100V-10A-Voltmeter-Ammeter-Red-LED-Amp-Dual-Digital-Volt-Meter-Gauge-Blue/32849656816.html

author: IanB
author_rank: Super Contributor
timestamp: February 27, 2018, 01:32:08 am
content: Quote from: JayMan07 on February 26, 2018, 09:57:49 pmI see. But it appears that a combo Pozidriv/Slot head bit is the right thing. A Pozidriv alone should work.The difference between Phillips and Pozidriv is that Phillips is designed to cam out at high torque where Pozidriv is designed grip tightly and not cam out.

author: JayMan07
author_rank: Regular Contributor
timestamp: February 27, 2018, 02:19:10 am
content: Quote from: IanB on February 27, 2018, 01:32:08 amYes I think you are right! I just ordered this... "Wiha 28320 #1 x 90mm Insulated SlimLineSlotted PozidrivTorque Screwdriver"I think I will have to grind it down to a slightly smaller diameter in order for the bit to fit inside of the screw terminal hole, but I believe that a #1 is the correct size (or close enough). I'll definitely try and give an update on how well it works.Currently what I use, and the best thing I have found so far is a klein 32581 with the point ground down on the #0 phillips

author: Neomys Sapiens
author_rank: Super Contributor
timestamp: February 27, 2018, 02:27:42 am
content: Quote from: ez24 on February 26, 2018, 08:42:50 amAFAIK it WAS the original intention. Until a lot of people complained about ill fitting screwdrivers.Then the mentioned bits and drivers appeared. But correctly sized flat screwdrivers fit way better than Pz or PH.

author: Shock
author_rank: Super Contributor
timestamp: February 27, 2018, 10:11:26 am
content: I believe those terminal block screws are Xeno #1 or #2.The Pozidrives are quite different, they are the ones people mistake for Phillips.A couple of the bits mentioned I think are actually for combo screws (see below).

author: Shock
author_rank: Super Contributor
timestamp: February 27, 2018, 10:26:16 am
content: This might also help.

author: paulca
author_rank: Super Contributor
timestamp: February 27, 2018, 11:10:02 am
content: Quote from: ez24 on February 26, 2018, 08:42:50 amIt's interesting because these screws appeared in almost every single UK plug for the main screw and the wire clamp until the early 2000s before all appliances sold were required by regulation to have a molded fitted plug as standard. They always have a full width flat slot and a smaller width cross. Although some only had a slot it.Whether their design intent was to allow both cross/star screw drivers or flat head screwdrives, or they were a special screw bit, the former types of screw driver both work in there and I can guarantee you that 99.999% of households use either a flat or cross bit to open plugs.

author: JayMan07
author_rank: Regular Contributor
timestamp: March 03, 2018, 12:19:13 am
content: Just a quick update. I ordered the slotted phillips #1 and the slotted pozi #1. I filed them both down to fit the screws better. The slotted pozi worked best, but the klein I was using originally was a very close second. I think as of now there is really no perfect screwdriver for these terminal screws and if you look really closely at them I think they were actually designed to cause a screw driver to slip, maybe to prevent over tightening. Even the part of the screw that is a flathead doesn't have walls that are 90 degrees. There is a slight angle to them like this \_/ and it causes the flat head to slip after a certain amount of torque. In short, these screws are just total garbage and I think I made a little progress, but mostly I just have to accept the fact that they are garbage.

author: system24seven
author_rank: Newbie
timestamp: March 03, 2018, 06:37:27 pm
content: Wera makes them, all the guys who I work with in entertainment have the Kraftform Kompact sets that include this driver in two sizes as 1000v rated.http://products.wera.de/en/screwdrivers_kraftform_plus__series_100_vde_165_i_pz_s_vde.html

author: JayMan07
author_rank: Regular Contributor
timestamp: March 04, 2018, 06:04:43 pm
content: Can you elaborate on what exact driver it is that Wera makes for these screws. The link just took me to the Wera home page. If it's just a slotted pozi or something like that I would say it probably isn't any better than the wiha drivers. These screws are very very unique and I think someone would have to exactly make the driver to fit the screw because a slotted phillips and slotted pozi just don't fit very well.