What the heck kind of terminal screw is this?!

[JayMan07]

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 terminals 

My 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?   

[DimitriP]

You need one of these: 

https://www.wihatools.com/insulated-tools/screwdrivers/terminal-block/insulated-combination-terminal-block-xeno-screwdrivers

[JayMan07]

Ok that does look right.  Would the number 1 size be the right size for those terminal bocks?

[SeanB]

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.

[JayMan07]

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.

[Cerebus]

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.

[langwadt]

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 terminals 

My 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?   

it made so sparky can stick what ever sharpened nail he calls a screw driver and last used as a pry bar in there

[JayMan07]

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.

Thank 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.

[IanB]

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.)

[IanB]

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.)

[ez24]

Ordered this

https://www.aliexpress.com/item/UXCELL-Booher-Authorized-75Mm-Bar-Length-Pz0-Pozidriv-Screwdriver-Repairing-Tool/32810809694.html

[paulca]

I thought these were just so you could use either a flat terminal screw driver or a generic "cross" head.

[ez24]

I thought these were just so you could use either a flat terminal screw driver or a generic "cross" head.

Nope

[JayMan07]

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.)

Yes 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  .

[ciccio]

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.)

Please add a link or a manufacturer's name and/or model.
I've googled for it but no results.
Best regards

[tautech]

Combo tip driver.



https://express.ecsnz.com/en/combo-tip-driver-pzfl2

Less push force is required for equivalent torque and therefore less strain on electrical HW mountings.

[Monkeh]

Oh, yay, yet another screwdriver...

Hello, world. Torx. We've had it a while.

[JayMan07]

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.)

Please add a link or a manufacturer's name and/or model.
I've googled for it but no results.
Best regards

It's a milwakee ECX bit...ok for outlets but won't work on these screws.

[JayMan07]

Oh, yay, yet another screwdriver...

Hello, world. Torx. We've had it a while.

I know I can't possibly imagine why anyone would design a fastener like the one I posted a picture of    There are so many other good options

[ez24]

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.html

The only thing I do not know is the size, so I just ordered this because I see there is a pz00 in the set

https://www.aliexpress.com/item/16pcs-percision-screwdriver-set-min-computer-screwdriever-Screwdriver-slotted-PH00-PH0-PH1-T6-T7-T8-T9/32536044000.html

Found 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.html

Looking 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

[IanB]

It's a milwakee ECX bit...ok for outlets but won't work on these screws.

I 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.

[JayMan07]

It's a milwakee ECX bit...ok for outlets but won't work on these screws.

I 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.

Yes I think you are right!  I just ordered this... "Wiha 28320 #1 x 90mm Insulated SlimLine Slotted Pozidriv Torque 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

[Neomys Sapiens]

I thought these were just so you could use either a flat terminal screw driver or a generic "cross" head.

Nope

AFAIK 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.

[Shock]

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).

[Shock]

This might also help.