Twist wires before using a wire nut?

[Ole Anderson]

So, do you twist your wires together before using a wire nut? Some manufacturers say it isn't necessary.

[Doug Dawson]

So, do you twist your wires together before using a wire nut? Some manufacturers say it isn't necessary.
Absolutely. It’s a mechanical connection, held in place by the wire nut (which also insulates the connection.)

[Julie Moriarty]

So, do you twist your wires together before using a wire nut? Some manufacturers say it isn't necessary.

We have joked on the jobsite many times about what the wire nut manufacturers say and then follows the countless stories about tracing out an electrical problem only to find a wirenut twist the culprit.

IF, and that's a big IF, you can get sufficient purchase on two small wires that grab the wires enough to twist them as you would with lineman's sidecutters, then maybe that will be a good splice. But try to grab 3 or 4 #12 wires using a wire nut and properly twisting them.

The manufacturers need to drop this silly claim.

[Julie Moriarty]

I just clicked "NO" because I was thinking about using a wire nut to twist wires. I can't change my vote but want everyone to know, at this point, the poll should be 3-0 in favor of twisting wires.

[Robert Engel]

Yes. I had a a neutral come loose in a junction box up in the attic.

Electrician had a heck of a time tracing it down, then schooled me about ALWAYS twisting before wire nutting, even if it’s just 2 wires.

[Tony Zona]

On occasion I have soldered the twist before screwing the wire nut on. Extreme, huh?

[Tom M King]

I always make a pretty twist counter-clockwise. I have a pair of needle nose pliers that don't open without help. They are "clamped" onto the wires, and the ends are twisted together, then the ends clipped. That leaves the wire nut to mostly just protect the twisted wires from touching anything else.

Soldering is not recommended.

[Rod Sheridan]

Interesting question, in Canada the electrical code stipulates that manufacturers installation instructions must be used.

In the case of Marrettes (wire nuts) all the manufacturers products I've purchased state not to twist the wires before installing the Marrette.

I don't twist the wires before insertion into the Marrette.............Rod.

[Zachary Hoyt]

I was told to always twist the wires before installing the wire nut, so I do. It makes sense to me.

[Aaron Rosenthal]

Like Julie says, my electrician here in Vancouver (Canada) always twists the wires together. But then he’s old school, and values his claim free insurance and low call back reputation.

[Frank Pratt]

Interesting question, in Canada the electrical code stipulates that manufacturers installation instructions must be used.

In the case of Marrettes (wire nuts) all the manufacturers products I've purchased state not to twist the wires before installing the Marrette.

I don't twist the wires before insertion into the Marrette.............Rod.

Rod, I'm a stickler for following the book, but sometimes you have to let common sense & experience take the driver's seat. For a couple of #14 wires, no problem. Just make sure the ends of the wire are all perfectly aligned & then twist it tight. If the wires don't end up twisted inside the wire nut, then it's not a good connections, period. Try doing it with 5 or 6 #12s. MUCH easier to twist first with linesman pliers, clip the ends flush, and then put on the wire nut.

BTW, I just checked the instructions for Marrette & Ideal wire nuts & both say to twist the wire nut on tightly, but don't forbid twisting the wires first. If the wires are not twisted after connection, then the wire nut was not twisted tightly enough.

[Frank Pratt]

I just clicked "NO" because I was thinking about using a wire nut to twist wires. I can't change my vote but want everyone to know, at this point, the poll should be 3-0 in favor of twisting wires.

I agree, and for that reason, I didn't select either answer.

[Matt Day]

Either way, I always give each wire a good tug after tightening the wire nut.

[Weogo Reed]

Hi Folks,

A wire nut is a compression fitting that changes the shape of the wires to
fill the gaps between them for extra contact area.
Also corrosion is reduced since air has less access to copper.

Tony Z, for four~five wires in a wire nut, soldering the wires before running a wire nut down on them can
be helpful for assuring all wires stay in the bundle, that one doesn't slip out.
But soldering can introduce other issues.
It takes a lot of heat to get four or five #12 copper wires hot. Do you have a really hot soldering iron?
Do you have melted insulation issues?
Soldering can embrittle wires right at the edge of the joint. This is probably
not an issue in a residential outlet, but might be on a vibrating machine.
For decades, most wire connections on airplanes have been compression, not solder.

Frank P, I use your twist and clip method for a bunch of wires.

Thanks and good health, Weogo

[Frank Pratt]

Soldering is forbidden by code in some situations, like fire alarm connections.

[Jim Koepke]

There should be a third answer, It depends.

jtk

[John Terefenko]

I always twist wires before wirenut. Was taught that way and no reason not to. There is more reasons against not twisting. Wire expands and contracts with heat. they can work lose of a wirenut if not properly secured. Why take a chance.

[Doug Garson]

I always make a pretty twist counter-clockwise. I have a pair of needle nose pliers that don't open without help. They are "clamped" onto the wires, and the ends are twisted together, then the ends clipped. That leaves the wire nut to mostly just protect the twisted wires from touching anything else.

Soldering is not recommended.
Aren't wire nuts made with right hand threads? Won't twisting the wires counterclockwise then twisting the wire nut on clockwise untwist the wires? What am I (or everyone else) missing? Oh and how do millennials with digital smart watches know which way to twist?

[Peter Kelly]

I'll twist the wires clockwise if I have the grave misfortune of having to use wire nuts. Wago or Polaris connectors otherwise.

[Jim Koepke]

Wire expands and contracts with heat.

This is also the reason given to me for not soldering junctions in crimp or twist connectors. The thermal changes can cause a solder joint to go 'cold,' causing more resistance in the joint. Eventually more heat could lead to junction failure. This isn't as critical in low voltage, low amperage circuits.

jtk

[Ed Aumiller]

Need a choice of "DEPENDS"... sometimes yes, sometimes no...

[Doug Dawson]

Need a choice of "DEPENDS"... sometimes yes, sometimes no...
A really good set of linesman pliers like the Knipex 0912240 https://www.amazon.com/09-12-240-9-5-Inch-Ultra-High/dp/B004LXXXXI/ref=sr_1_2?crid=76NHLZ1ZNWG7&dchild=1&keywords=knipex+0912240&qid=1614814306&sprefix=Knipex+0912240%2Ctools%2C193&sr=8-2 will make you want to twist wires all day long. I think sometimes people don’t want to do it because they’re using marginal equipment.

[Jim Becker]

I do a very careful and tight twist to get a great mechanical connection, snip the end clean and then screw on the wire nuts. If I'm feeling really anal, I'll tape them, too.

[Doug Garson]

I do a very careful and tight twist to get a great mechanical connection, snip the end clean and then screw on the wire nuts. If I'm feeling really anal, I'll tape them, too.
Counterclockwise?

[Mike Henderson]

I twist the wires before using a wire nut.

Mike

[Charlie Velasquez]

I have moved to Wagos for almost all 14# and 12# connections, solid and stranded.

Julie, Frank Pratt, what are your thoughts on Wagos?

[Frank Pratt]

A really good set of linesman pliers like the Knipex 0912240 https://www.amazon.com/09-12-240-9-5-Inch-Ultra-High/dp/B004LXXXXI/ref=sr_1_2?crid=76NHLZ1ZNWG7&dchild=1&keywords=knipex+0912240&qid=1614814306&sprefix=Knipex+0912240%2Ctools%2C193&sr=8-2 will make you want to twist wires all day long. I think sometimes people don’t want to do it because they’re using marginal equipment.

Ain't that the truth. Some other good brands are Ideal, Klein and Channellock. I don't like using brand new linesman pliers because the jaws are too grippy & scrape up the wires. After a bit of wear they get real nice; just enough grip, yet smooth enough to allow the wire to slide as you twist. They last a long time like that, until you use them for a hammer the wrong way or cut a live cable :(

[Frank Pratt]

I have moved to Wagos for almost all 14# and 12# connections, solid and stranded.

Julie, Frank Pratt, what are your thoughts on Wagos?

I haven't used thousands of them yet, but I like them. I didn't want to because of the reputation of the back stab receptacles. But after lots of research & no failures with them personally, I'm a fan. Especially the lever lock type that can easily be removed. They're lots more money though.

[Julie Moriarty]

Julie, Frank Pratt, what are your thoughts on Wagos?
A good splice is one that creates the most surface contact between conductors, with that contact being secure, in that the incidence of it failing over time is minimal.

Press fittings, those that have a thin blade ready to capture and hold the wire, have a very small surface contact between the conductors. The conductors being the wire and the capture blade.

I have made splices on loads as large as 2000 amps. These are all 3 phase, 480 volts. In every case the focus has always been on maximizing the surface contact between the conductors and making sure the connection is very tight. Loose connections always fail, eventually.

That knowledge trickles down to every splice we make. I can't remember how many times I personally have seen or how many times I have heard guys on the jobs tell the stories about bad splices but the lessons learned is do everything you can to make a safe and secure splice. Simplicity is not always the best answer.

So to answer your question, I do not consider Wagos safe and secure splicing connectors. In time, they will eventually fail.

[Bruce King]

Guess why they make the winged nuts vs knurled.

[Doug Dawson]

Counterclockwise?
It depends on what direction you’re looking at the end from. If you sight down the wire towards the end, it’s counterclockwise. :^)

[Doug Garson]

It depends on what direction you’re looking at the end from. If you sight down the wire towards the end, it’s counterclockwise. :^)
Hmmm, I'm picturing 3" of wire coming out of a junction box and getting my head and the pliers and my arm between the wall and the end of the wire so I can sight down the wire and turn the wire counter clockwise, guess I gotta do more yoga. :eek:

[Doug Dawson]

So to answer your question, I do not consider Wagos safe and secure splicing connectors. In time, they will eventually fail.
The main “in principle” complaint I’ve heard about the Wago’s is that the springs may lose strength with repeated heat cycles in high-current operation. This doesn’t apply when used with grounding wires or with most modern lighting systems. They’re especially convenient in older/smaller boxes. When putting newer larger devices into an older box, they may be the only alternative to ripping out the older box and sticking in a new one.

BTW, I’m referring to _actual_ Wago’s like the German-made 221, not the Chinese knock-offs or the “twisty-lock” push-in’s.

[Frank Pratt]

Just by coincidence, a youtube popped up a couple of days ago that tested Wago vs wire nuts. The guy was running massive overcurrent through & measuring the temp rise. The Wagos did heat up a little more than the wire nut connections, but that was at something like 60A running through a 20A connector.

We think we know that something will fail, but until there is evidence of that, it's just a guess. To make an accurate assessment, one needs data and I haven't been able to find any that says a Wago is less reliable than a wire nut when used within the ratings. I don't think it can be argued that there is more chance of an incorrectly done connection with a Wago though. I'd love to see a study that compares the reliability of statistically significant numbers of both types of connections.

[Ole Anderson]

When I wired my new home under a homeowners permit I didn't twist the wires first. Inspector didn't have a problem with it. That was about 1975 when the prevailing wire nuts had a soft plastic coating, not the wingnuts like you see now. I have since found two that failed open with one short wire not engaging the nut properly. Since then I always twist them first. Now I have Klein lineman's pliers which work good. My good Knipex lineman's are now a handy dandy stripper after cutting a live 20 amp circuit that had a bad breaker that didn't trip. All breakers have since been replaced.

[Doug Garson]

If Wagos are approved to be used in code applications, I would expect that the manufacturer would have to provide documented extensive testing to prove their reliability. They are CSA and UL approved in addition to any testing documented by the manufacturer. Now do you push the wires in or stand on the other side and pull them in? :cool:

[Bruce King]

That 1975 breaker that didn’t trip, let me quess, it was a FPE panel. If anyone has an FPE or Zinsco it needs to be replaced before a fire.


When I wired my new home under a homeowners permit I didn't twist the wires first. Inspector didn't have a problem with it. That was about 1975 when the prevailing wire nuts had a soft plastic coating, not the wingnuts like you see now. I have since found two that failed open with one short wire not engaging the nut properly. Since then I always twist them first. Now I have Klein lineman's pliers which work good. My good Knipex lineman's are now a handy dandy stripper after cutting a live 20 amp circuit that had a bad breaker that didn't trip. All breakers have since been replaced.

[Ole Anderson]

That 1975 breaker that didn’t trip, let me quess, it was a FPE panel. If anyone has an FPE or Zinsco it needs to be replaced before a fire.
It was a Murray.

[ChrisA Edwards]

Never heard of Wagos until this thread. Here's the video I think Frank is referring to.


https://www.youtube.com/watch?v=B1pmuRsf1co

[Tom Stenzel]

I had an electrical safety class years ago taught by a retired New York Power and Light construction supervisor. He said that NEC code required all connections had to be mechanically secure before the wire nut went on. That meant twisted. He had stories of electricians getting knocked off of ladders because of wires popping out of wire nuts.

I don't know if it's in NEC code or not but I've always twisted the wires.

-Tom

[Frank Pratt]

Never heard of Wagos until this thread. Here's the video I think Frank is referring to.


https://www.youtube.com/watch?v=B1pmuRsf1co

Yes, that's the one.

[Frank Pratt]

An issue with not twisting is that when there are more than a couple of wires, it can be tough to twist the wire nut on hard enough to make the twist & hold the nut on securely. the 'wings' on some help a lot, but if you don't have strong hands, you better be twisting with pliers.

[John K Jordan]

I always twist wires before wirenut. Was taught that way and no reason not to. There is more reasons against not twisting. Wire expands and contracts with heat. they can work lose of a wirenut if not properly secured. Why take a chance.

I always twist wires before using the wire nut. I twist two 14ga and thinner by hand; 12ga and more than two conductors I twist with pliers.

[Peter Kelly]

I don’t think wire nuts are even permitted for use in UK or Continental Europe, all lever or screw terminal block connectors nowadays. The only downsides to Wagos that I can see are the cost and that they’re a bit fiddly to use with stranded wire.

Another advantage of Wagos - unlike wire nuts, you can actually see quite clearly whether you’ve got the wire end seated all the way inside the connector.

[Jim Koepke]

I have made splices on loads as large as 2000 amps. These are all 3 phase, 480 volts. In every case the focus has always been on maximizing the surface contact between the conductors and making sure the connection is very tight. Loose connections always fail, eventually.

While working in transportation any wiring with high voltage or current would be spliced with crimp connectors using precision jaws and a pneumatic driver.

Do they make Wago connectors for such loads?

jtk

[Roger Feeley]

I never did but I sure will in the future. You guys that are twisting 5 #12’s into one nut are scaring me. Wouldn’t you use some sort of terminal strip for that many?

interesting comment about the Wago connectors. I love the look of them but wondered if code allows them.

[Doug Dawson]

I never did but I sure will in the future. You guys that are twisting 5 #12’s into one nut are scaring me. Wouldn’t you use some sort of terminal strip for that many?

interesting comment about the Wago connectors. I love the look of them but wondered if code allows them.
Yes, they’re UL listed for up to 5 #12’s. :) There’s also a version that works with 10ga wire.

[John K Jordan]

I never did but I sure will in the future. You guys that are twisting 5 #12’s into one nut are scaring me. Wouldn’t you use some sort of terminal strip for that many?

interesting comment about the Wago connectors. I love the look of them but wondered if code allows them.

I keep some wire nuts that are HUGE. No problem with 5 wires, but it is easier with fewer. The wire nuts are compact compared to the multi-tap connectors and have excellent insulation. I've used wire nuts for up to #6 (but not with five wires!)

[Wade Lippman]

No one mentioned stranded wire. While I always twist solid wire, I have never managed to twist stranded. For that I shove the wire in the wire nut and trust the wire nut to twist it. I never took one off to see how successful it was.
For more than 2 wires I use wagos. I never mastered twisting 3 or 4 wires together and was thrilled not to muddle through it.

[John Terefenko]

I never did but I sure will in the future. You guys that are twisting 5 #12’s into one nut are scaring me. Wouldn’t you use some sort of terminal strip for that many?

interesting comment about the Wago connectors. I love the look of them but wondered if code allows them.


As an electrician, that is no problem. 2 tricks are to cut the ends longer than needed and to lay them straight against each other with all insulation ends equal. Then with lineman's grab all wires and twist. Now cut off ends just long enough to be cover with wirenut. Use a blue scotchlock wirenut and good to go. Easy.

[Peter Kelly]

Easy until you need to pack a twisted group of 5 number 12s into a box with any other wiring. Nothing will give you arthritis faster.

[Kev Williams]

Wish I'd known about these Wago connectors a year ago when I was changing out the old bathroom fan for the newfangled one with lights too..
453683

...squoze into this 2-gang box is a combo light switch/GFI plug (which is pretty fat) and the even fatter switch for the new fan/light...
453684

Not much room left in the box for all the h/n/g wires & wirenuts needed that feed the GFI outlet, the outlet on the other side of the wall, the main room light, the fan and the fan light. Got all the wires connected okay but as the pic shows, there was no way to push the new fan/light switch flush to the wall. Ended up making a spacer to fit between plate and the wall, and even then the new switch is cockeyed...

Four of these things should tidy up everything and leave plenty of room for the switches to screw down flush...
453682

Oh-- as to the poll- I'm in the 'depends' group ;) --but usually I DO twist the wires first-- :)

[Jason Roehl]

As someone who does some repair-type electrical work in a commercial setting, I hate twisted wires for a number of reasons. The biggest is that it is difficult to get one wire out of a bundle. Then, when the nut has to go back on, the curly-qued ends have to be trimmed off because the wire is 30 years old and brittle—it can’t be straightened and re-twisted. That leads to the problem of there already may not be a long enough lead of wire in the box to re-strip the wire and join it back up with the bundle.

I’ve certainly seen a wire or two come loose out of a bundle that’s not twisted, but I check each wire after I put the nut on. Stranded wire I’ll usually twist together, solid I won’t in most situations, since I’m usually using #12 or #10 wire.

[Stephen Tashiro]

It depends on what direction you’re looking at the end from. If you sight down the wire towards the end, it’s counterclockwise. :^)

What's the direction for twisting on the wire nut after the wires are twisted? Is the nut twisted so it it tends to tighten the twist of the wires? (which I assume would also be described as "counterclockwise" if the twist of the wire is described that way) - or is the wire nut twisted in the opposite direction?

[Doug Dawson]

What's the direction for twisting on the wire nut after the wires are twisted? Is the nut twisted so it it tends to tighten the twist of the wires? (which I assume would also be described as "counterclockwise" if the twist of the wire is described that way) - or is the wire nut twisted in the opposite direction?
The wire nut is twisted in the same direction as the twist of the wire, which is clockwise as you’re looking down at the pointy end of the wire (I can’t do yoga either.)

[Doug Garson]

Yes, twist the nut the same direction as you twisted the wire otherwise you would loosen the wires. Holding the wire in your left hand and the wire nut in your right you turn the wire nut clockwise. I just assumed the counterclockwise post was a typo that no one noticed.

[Doug Dawson]

Yes, twist the nut the same direction as you twisted the wire otherwise you would loosen the wires. Holding the wire in your left hand and the wire nut in your right you turn the wire nut clockwise. I just assumed the counterclockwise post was a typo that no one noticed.
I just assumed he was in the Southern Hemisphere.

Which half of the bottle do you want, the top half or the bottom half? :^D

[John K Jordan]

Yes, twist the nut the same direction as you twisted the wire otherwise you would loosen the wires. Holding the wire in your left hand and the wire nut in your right you turn the wire nut clockwise. I just assumed the counterclockwise post was a typo that no one noticed.

Inside the wire nuts is a conical coiled spring. Twisting clockwise (viewed from the end), the same as tightening a screw or bolt, is necessary to tighten the grip of the spring on the wires. Righty tighty. This actually leaves grooves in the solid copper wire ends. Turning counterclockwise will loosen the connection, just like unscrewing a bolt. Very small wire nuts once widely used for stranded-stranded or stranded-solid connections in lighting fixtures don't have a spring but conical plastic threads which grip the wires. There are better connectors available now but they are more expensive.

It is important to use a wire nut sized properly for the number and size of conductors. Larger wire nuts these days often have finger tabs making it easier to apply more force. After tightening some advocate for taping the wire nut to the wires, perhaps out of habit, but from what I read this is not necessary.

[Jim Jackson Wyoming]

In 40 plus years of being an electrician, I have installed thousands of wire nuts. There has been very few times I've twisted the wires prior to installing the wire nut. It is not necessary, and a royal pain in the back side to try to pull a wire from the bundle of wires if needed.

IF you use the proper size wire nut, and IF you install it properly twisting the wires together is not needed.

Instructions may not forbid twisting wires together, but I have not seen any that say to do it prior to installation.

[Thomas McCurnin]

I twist, except stranded to solid. Note that if one does not twist, and torques down the wire nut, the wires will twist inside the wire nut.

[Frank Pratt]

I twist, except stranded to solid. Note that if one does not twist, and torques down the wire nut, the wires will twist inside the wire nut.

Yep, and if they aren't twisted inside the wire nut, then it was not twisted hard enough & there will be a poor connection.

[Jason Roehl]

I twist, except stranded to solid. Note that if one does not twist, and torques down the wire nut, the wires will twist inside the wire nut.

I’m pretty sure most wire nuts would break before you got 10- and even 12-gauge solid wire to twist inside a wire nut, especially if it’s more than two wires.

I’m with Jim J—no need to pre-twist. I think it just work-hardens solid copper wire anyway, making it more likely to break (I’ve removed quite a few old wire nuts that had a small piece of wire left in them—the wires were always twisted together). When you’re working in an old, fairly full J-box, losing 1/2” off a wire because it was twisted can make things very difficult to button back up.

[Bill Dufour]

I ran into a different wire nut on my lathe. It was probably German or British. Looked like a regular wire nut. I unscrewed the plastic shell and inside was a brass thimble with the wires still locked in. It had a small setscrew from the side to lock the wires in place. The plastic cover just insulated the thimble and unscrewed to allow access to the screw. Similar to a polaris connector in a way.
Bill D

[David Buchhauser]

Absolutely. It’s a mechanical connection, held in place by the wire nut (which also insulates the connection.)


Yes. Particularly on #10 and #12 solid conductor "Romex" cable.

[Stan Coryell]

I ran into a different wire nut on my lathe. It was probably German or British. Looked like a regular wire nut. I unscrewed the plastic shell and inside was a brass thimble with the wires still locked in. It had a small setscrew from the side to lock the wires in place. The plastic cover just insulated the thimble and unscrewed to allow access to the screw. Similar to a polaris connector in a way.
Bill D

Bill,
I worked somewhere that used these.
Ideal 30-1294G
https://www.zoro.com/ideal-mechanical-conn-set-screw-10-18-awg-pk10-30-1294g/i/G2092194/?utm_source=google&utm_medium=surfaces&utm_campaign=shopping%20feed&utm_content=free%20google%20shopping%20clicks&gclid=CjwKCAjw9MuCBhBUEiwAbDZ-7vgwUhf-auDCnCHK13CG6aXIR_YD9qHON4XRNI0jSxXPLErpmXjkmRoC0X oQAvD_BwE

I don't remember where. GE maybe.

[Ronald Blue]

I ran into a different wire nut on my lathe. It was probably German or British. Looked like a regular wire nut. I unscrewed the plastic shell and inside was a brass thimble with the wires still locked in. It had a small setscrew from the side to lock the wires in place. The plastic cover just insulated the thimble and unscrewed to allow access to the screw. Similar to a polaris connector in a way.
Bill D

We use this style on a machine that has 3 phase motors to drive the heads. They work well. They are vibrating units for engaging the ballast and they don't loosen. In this case it's stranded wire which might work better. Slip wires in and tighten the set screw, then put the cap on. I don't think they are available in more than a couple sizes.

[Doug Garson]

I ran into a different wire nut on my lathe. It was probably German or British. Looked like a regular wire nut. I unscrewed the plastic shell and inside was a brass thimble with the wires still locked in. It had a small setscrew from the side to lock the wires in place. The plastic cover just insulated the thimble and unscrewed to allow access to the screw. Similar to a polaris connector in a way.
Bill D
I have a few of those in my stash of wire nuts, one is labelled "PAT MARR NO2 1924", a couple are just labelled "MARR NO2" don't recall where or when I got them. I remember using them when I rewired my house back in the 70's or 80's. Hard to photograph but here's one.
454615

[Tom M King]

Has anyone used the two color, 3M wire nuts? I just ordered some to try, the next time I need to use any.

[Doug Dawson]

Yes. Particularly on #10 and #12 solid conductor "Romex" cable.
Here’s how I remember it. If a wire comes along, you must twist it. Twist it good. Sing it with me now... :^)