Baltimore Francis Scott Key Bridge collapse

[floobydust]

It's weird the ship is 9 years old and a DIN-rail terminal block fails now?
Switchboards made by Hyundai but using Wago?
Even if this is root-cause, the power system is redundant and switching to the backup appears to have been also bungled.

[nctnico]

I've spec'd and used the Wago spring clamp terminal blocks to 40A (PCB) and they are excellent. They are typically used with wire ferrules. Used on locomotives because temp cycles and vibration cause screw-type terminal blocks to loosen with age. Unpopular in North America though, compared to Europe.

Other brands of spring clamp I've tried are crap. Hear that Weidmuller lol.

If you read carefully, you'll read that the NTSB removed a terminal similar to Wago. They don't specify which brand it actually is.

[nctnico]

some people on the forum were saying that it turns out the dumb american wire nut has a kind of welding action going on akin to wire wrapping which improves its reliability compared to wago connectors if used properly. The ones with the metal spiral inside

Not welding. But like wire-wrapping, you do get a very large, gas-tight contact surface when using a wire nut which has a coil made from rectangular wire. But you'll need to buy/use high quality wire nuts. Not the fake crap you find at home improvement stores.

Then again, wire nuts are not practical for wiring up control / distribution panels.

[AVGresponding]

some people on the forum were saying that it turns out the dumb american wire nut has a kind of welding action going on akin to wire wrapping which improves its reliability compared to wago connectors if used properly. The ones with the metal spiral inside

Not welding. But like wire-wrapping, you do get a very large, gas-tight contact surface when using a wire nut which has a coil made from rectangular wire. But you'll need to buy/use high quality wire nuts. Not the fake crap you find at home improvement stores.

Then again, wire nuts are not practical for wiring up control / distribution panels.

You also need to be skilled in their use, which introduces the human fail factor at a low bar; harder to muck up a spring connector

I've spec'd and used the Wago spring clamp terminal blocks to 40A (PCB) and they are excellent. They are typically used with wire ferrules. Used on locomotives because temp cycles and vibration cause screw-type terminal blocks to loosen with age. Unpopular in North America though, compared to Europe.

If a bonehead twists the screwdriver (instead of just pushing it in) to open the clamp, or uses the wrong size screwdriver, or pry's, it can wreck the terminal block inside by deforming the spring.
I would suspect that is what happened, improper assembly.

When panels are being built, we have a "tug'n tighten" requirement that you tug on all wires after assembly. I've had a few electricians with weak hands leave screw-terminal wiring really loose (just like idiot crimp-connecting) and the wire pulls out.
If I find a few loose connections, I flip out and demand everything gets re-tightened or re-crimped.

Out in the field, I have encountered control panels full of loose wires and spent 1/2 hour redoing all, which gets rid of many problems.

Other brands of spring clamp I've tried are crap. Hear that Weidmuller lol.

Hence the mandating of torque screwdrivers in electrical installation in the UK (yeah, very few sparks use them, I'm usually the only one on site)

[David Hess]

Older industrial equipment which must operate in a difficult environment with vibration often used barrier strips with wires terminated with spade or ring terminals.  I am not sure how they prevent the screws from backing out, but it seems to rarely happen and they should be checked periodically.

[floobydust]

I've spec'd and used the Wago spring clamp terminal blocks to 40A (PCB) and they are excellent. They are typically used with wire ferrules. Used on locomotives because temp cycles and vibration cause screw-type terminal blocks to loosen with age. Unpopular in North America though, compared to Europe.

Other brands of spring clamp I've tried are crap. Hear that Weidmuller lol.

If you read carefully, you'll read that the NTSB removed a terminal similar to Wago. They don't specify which brand it actually is.

I did read the NTSB update a few times.
Photo caption: "Exemplar terminal block identical to model removed from ship. (Source: WAGO)"

[tom66]

Is this possibly the most consequential failure of a single conductor ever?

One conductor causes the death of six roadworkers and the destruction of a bridge which will cost the best part of $2bn to rebuild, in addition to the economic loss to the region.

Makes you think how many other ticking timebombs there are like this in systems - just waiting for the Swiss cheese to line up.

It's got to be up there with something like Swissair 111 where it's thought that a faulty connection in the in-flight entertainment system led to a rapidly spreading fire which eventually disabled flight controls and caused the plane to nosedive, killing all 229 passengers on board.

[floobydust]

Major disasters I find are caused by at least two or more faults.
Swissair 111 second failure was the plastic air ducts did sorta meet the vertical flame tests but not in reality. I saw it, it was super creepy - glowing orange hot plastic, sitting there and after 10 seconds foof it would self-ignite and start burning. Aftermath I thought they updated the test standard to include a 30 second wait for self-ignition to not happen or something. I also recall the ducts already being replaced in aircraft because of this, before the place crach - it was already a known safety problem.

Older industrial equipment which must operate in a difficult environment with vibration often used barrier strips with wires terminated with spade or ring terminals.  I am not sure how they prevent the screws from backing out, but it seems to rarely happen and they should be checked periodically.

On screw terminals, sometimes initial torque is low. All day long you turn a screwdriver as your job, and after a while you get tired, carpal tunnel etc. and things are not tightened much.
It's the potpourri of metals involved. Steel, copper, aluminum and then their plating - nickel, zinc, chromium etc. DIN-rail terminal blocks are made to a price point and some are very cheap. In a marine environment I have no experience what works well in the humidity and salt. There are no lock-washers in these terminal blocks.
With time, I have seen many connection screws go loose, then they heat up and things melt. That's why the spring-cage has an advantage.

Considering this is multi-billion $ incident, I could see everyone getting sued, terminal block manufacturer as well.

[tom66]

I do foresee Wago (or realistically their insurers) picking up some of the bill here.  And then every datasheet will come with a one-page sheet detailing how they accept no liability in the future unless the connector is regularly tested, which no one will realistically do.  All the lawyers will laugh on their way back to the bank and nothing actually gets better.

Remember how Securitas, the company that provided the security guard being paid $15 an hour at the Miami apartment block, settled for over $500mn because they were deemed partially negligent for the incident and resulting deaths.  Their security guard was supposed to be able to recognise the signs of a building collapse and take appropriate action.  Yeah, in the 10 or so minutes from the first signs of danger to the building collapsing, I think most here would fail to appreciate the severity unless they held a structural engineering degree.  The actual company that deficiently built the apartment block is long gone so you can't sue them.  Doesn't seem reasonable but that's how these things go.

[nctnico]

I've spec'd and used the Wago spring clamp terminal blocks to 40A (PCB) and they are excellent. They are typically used with wire ferrules. Used on locomotives because temp cycles and vibration cause screw-type terminal blocks to loosen with age. Unpopular in North America though, compared to Europe.

Other brands of spring clamp I've tried are crap. Hear that Weidmuller lol.

If you read carefully, you'll read that the NTSB removed a terminal similar to Wago. They don't specify which brand it actually is.

I did read the NTSB update a few times.
Photo caption: "Exemplar terminal block identical to model removed from ship. (Source: WAGO)"

But that doesn't say it is the same manufacturer. Products from Wago (and Phoenix) are widely cloned so an 'identical model' says nothing about the actual manufacturer. If the NTSB had determined the terminal block they removed from the ship is made by Wago, they had written that the terminal block they removed from the ship was made by Wago. But that is not what they wrote at all. Notice the word 'Exemplar'.

[Someone]

I do foresee Wago (or realistically their insurers) picking up some of the bill here.  And then every datasheet will come with a one-page sheet detailing how they accept no liability in the future unless the connector is regularly tested, which no one will realistically do.  All the lawyers will laugh on their way back to the bank and nothing actually gets better.

Most volume product data sheets already have something along the lines of that: "not authorized for use in safety-critical applications" etc

[johansen]

Older industrial equipment which must operate in a difficult environment with vibration often used barrier strips with wires terminated with spade or ring terminals.  I am not sure how they prevent the screws from backing out, but it seems to rarely happen and they should be checked periodically.

I don't see the screws fail when torqued correctly, except on the aluminum lugs on modern electrical panels and aluminum wire. those burn up all the time (and as a friend says, i don't use a torque wrench and i don't know any electricians who do)

stranded wire crimped into anything, can slowly corrode in a manner in which every single strand becomes insulated from each other, and over time the wire becomes higher and higher resistance.

i've found these types of failures across a wide variety of equipment:

several almost open circuit ring terminals in a 1983 era 50kw generator with all of 300-400 hours of run time on it. the battery cable which is probably 19 groups of ~12 gauge stranded wire, also failed when only 1 group of those 19 strands carried all the current and melted 8 inches of the outer jacket, which had it been bundled with other wires, easily could have resulted in a fire if it had shorted out against something.

the factory oem battery cable crimp on my 1996 toyota. i heated it with plumbers tinning flux and wicked solder into the crimp. it was a very nice looking brass or bronze terminal with a factory, very tight crimp, nearly 1 inch long, on a 1 gauge ish wire. after fixing it, engine turned over a little faster and the ring terminal did not get HOT during cranking.

trusting a spring clip on a stranded wire is insane in my opinion.

trusting a solid wire with a spring clip on a ship subject to heavy vibration, is as retarded as trusting backstabbed american outlets..

[David Hess]

Older industrial equipment which must operate in a difficult environment with vibration often used barrier strips with wires terminated with spade or ring terminals.  I am not sure how they prevent the screws from backing out, but it seems to rarely happen and they should be checked periodically.

stranded wire crimped into anything, can slowly corrode in a manner in which every single strand becomes insulated from each other, and over time the wire becomes higher and higher resistance.

If that happens, then it was not properly crimped.  Crimping pressure is suppose to weld the wires to the inside of the terminal, and with a gas tight weld, corrosion cannot get between the surfaces.  I tend to solder after crimping although wicking creates other problems.

the factory oem battery cable crimp on my 1996 toyota. i heated it with plumbers tinning flux and wicked solder into the crimp. it was a very nice looking brass or bronze terminal with a factory, very tight crimp, nearly 1 inch long, on a 1 gauge ish wire. after fixing it, engine turned over a little faster and the ring terminal did not get HOT during cranking.

I had to splice and extend my battery harness after the side terminals on the original starter battery corroded.  There was not much room, so I used bus bar wire to wrap the stranded cables together for about an inch of overlap and then soldered them.  I replaced the side terminals with bronze/brass top marine terminals.  I should solder the stranded battery cables where the terminals clamp, but have not done that yet.

trusting a spring clip on a stranded wire is insane in my opinion.

trusting a solid wire with a spring clip on a ship subject to heavy vibration, is as retarded as trusting backstabbed american outlets..

Yea, I am amazed the American style spring clips do not cause more fires.  I tend to use the screw terminals.

[johansen]

Older industrial equipment which must operate in a difficult environment with vibration often used barrier strips with wires terminated with spade or ring terminals.  I am not sure how they prevent the screws from backing out, but it seems to rarely happen and they should be checked periodically.

stranded wire crimped into anything, can slowly corrode in a manner in which every single strand becomes insulated from each other, and over time the wire becomes higher and higher resistance.

If that happens, then it was not properly crimped.

https://www.amazon.com/Ferrule-Crimping-Tool-Kit-0-08-10mm%C2%B2/dp/B07PJK2VNT/

ever seen these things in professional equipment?  aint going to get a gas tight crimp with them...

[David Hess]

https://www.amazon.com/Ferrule-Crimping-Tool-Kit-0-08-10mm%C2%B2/dp/B07PJK2VNT/

ever seen these things in professional equipment?  aint going to get a gas tight crimp with them...

Louis Rossmann did a video which mentioned defective crimp connectors from Chinese vendors on Amazon:

https://youtu.be/7trdHLtsFKM?si=Wed39PLgyylyreTP

[tooki]

Older industrial equipment which must operate in a difficult environment with vibration often used barrier strips with wires terminated with spade or ring terminals.  I am not sure how they prevent the screws from backing out, but it seems to rarely happen and they should be checked periodically.

stranded wire crimped into anything, can slowly corrode in a manner in which every single strand becomes insulated from each other, and over time the wire becomes higher and higher resistance.

If that happens, then it was not properly crimped.

https://www.amazon.com/Ferrule-Crimping-Tool-Kit-0-08-10mm%C2%B2/dp/B07PJK2VNT/

ever seen these things in professional equipment?  aint going to get a gas tight crimp with them...

What “these things” do you mean? No-name ferrules and a no-name crimper, or ferrules in general? Because yes, you see ferrules in professional equipment all the time. And yes, you get a gastight crimp with the correct tool.

[coppercone2]

I see people buy no name wago at work because "why is it so expensive?!?!!"

if you do the test its pretty easy to find what happens. if you do the paper clip test, their stuff breaks with 1/2 of the bends. and thats just the easy one to find. its probobly built from shitty pot brass rolled into sheets and shitty plated. the battery contacts nickel for instance, 2 bends. the name brand 8$ piece of "its a ripoff" survived 4-5 back and forth bends

when I am around engineers in a building sometimes I feel very thankful they strictly forbid anyone doing anything with the outlets or lights LOL. i can do python so i am smarter then the interconnect people's over priced stuff, it looks the same!!!

some hot shot always thinks their hot shit because they THINK they figured out a way to save a dollar.

if you cast it inproperly it absorbs air like seltzer water and becomes shitty copper. thats not even if you have pot copper. *mind blown*

and the amount of shit I have seen go wrong with a plating bath makes me think that the prices we see right now for interconnects are VALUE prices. its so god damn touchy to get it right . You need constant vigilance with all those processes. it costs money. its not magically gonna get cheaper.


Spend a few hours reading about the physics of plating and you WILL be humbled.


With all the scandals right now in the airline industry and others with counterfeit parts, and the huge amount of creative fraud going on with wire (i.e. copper clad copper wire, dirty electroplated copper that has 30% conductivity of the element), would you really be surprised if the technicians and builders did their job right, used the right torque, and it turns out it was like porous & contaminated metal that yielded at an unusually low pressure?? if they can get counterfeit titanium into a air liner, how easy is it to get bogus wagos or crimps into some ship ?? no one even makes a fuss about ships usually. their super low key. Its a simple device but a spring has to be exactly correct to work properly for the expected life time!!!!!

[floobydust]

The ship's environment is high humidity and salt air, so plating would be very important. Few manufacturers test for this. You would think this rules out the cheap stuff...

I had specified Phoenix Contact UK5-HESI USD $9.56 ea. when complaints started coming in, they would jam and the handle break off. When I dug in I found manufacturing had been moved over to china and the moulds, tolerances, plastics etc. had changed. Small but noticeable differences and the end product not great nor being fixed after I complained.
Now, had the made-in-Germany pricing changed? No, not at all. You offshore to china and a get minimum 10-20x savings. This is the new business model- offshore and reap profits.
Aliexpress Phoenix Contact Store lol pic related springs come pre-salted and oxidized! 

Not to blame the terminal block, but we don't know COO for the possible original Wago 280-681
Oops one problem with china is they copy the IP that you gave them, stupid naive Westerner.
Wonke Electric Co. or similar  Aliexpress cheap parts, note the spring is basically shit and hidden though in the cage, tolerances pretty loose. Unknown plating and metals.

Would you use these on a big job?

$0.50 each compared to DigiKey asking USD $2.81/100-lot (CAD $4.06) for the Wago 280-681 !

I'm saying the temptation to save money is huge, on these terminal blocks. 100's are used in these panels. Seems odd Hyundai? used Wago in these panels.

[coppercone2]

shit plating + vibration = flaking

flaking + corrosion = failure

[tooki]

The ship's environment is high humidity and salt air, so plating would be very important. Few manufacturers test for this. You would think this rules out the cheap stuff...

I had specified Phoenix Contact UK5-HESI USD $9.56 ea. when complaints started coming in, they would jam and the handle break off. When I dug in I found manufacturing had been moved over to china and the moulds, tolerances, plastics etc. had changed. Small but noticeable differences and the end product not great nor being fixed after I complained.
Now, had the made-in-Germany pricing changed? No, not at all. You offshore to china and a get minimum 10-20x savings. This is the new business model- offshore and reap profits.
Aliexpress Phoenix Contact Store lol pic related springs come pre-salted and oxidized! 

Are you absolutely certain it was moved to China? The Phoenix Contact website right now says those are manufactured in Turkey, so if you are correct about it having moved to China, then they actually moved it back!

Aliexpress Phoenix Contact Store lol pic related springs come pre-salted and oxidized! 

You know that's not Phoenix Contact selling there, right? If it's genuine Phoenix Contact product, it's just a reseller.

The ship's environment is high humidity and salt air, so plating would be very important. Few manufacturers test for this. You would think this rules out the cheap stuff...

I had specified Phoenix Contact UK5-HESI USD $9.56 ea. when complaints started coming in, they would jam and the handle break off. When I dug in I found manufacturing had been moved over to china and the moulds, tolerances, plastics etc. had changed. Small but noticeable differences and the end product not great nor being fixed after I complained.
Now, had the made-in-Germany pricing changed? No, not at all. You offshore to china and a get minimum 10-20x savings. This is the new business model- offshore and reap profits.
Aliexpress Phoenix Contact Store lol pic related springs come pre-salted and oxidized! 

Not to blame the terminal block, but we don't know COO for the possible original Wago 280-681
Oops one problem with china is they copy the IP that you gave them, stupid naive Westerner.
Wonke Electric Co. or similar  Aliexpress cheap parts, note the spring is basically shit and hidden though in the cage, tolerances pretty loose. Unknown plating and metals.

Would you use these on a big job?

$0.50 each compared to DigiKey asking USD $2.81/100-lot (CAD $4.06) for the Wago 280-681 !

Wago products are extremely expensive on Digikey. Coincidentally, I actually just placed a big order today directly from Wago. (I also ordered another couple hundred bucks or so of Phoenix Contact stuff from Digikey and Mouser today.)

My employer has an extremely good discount at Wago, so we would pay under USD $0.70 each for 280-681, in a box of 100. List price here is about $1.75 per piece. Given the discounts Wago will give when ordering directly, the $0.50 for a knockoff is extremely unattractive. That tracks with the pricing for AliExpress terminal blocks in general -- they are no bargain, often costing exactly the same as original Wago, Phoenix, or Weidmüller.

[coppercone2]

but you fail to take into account the cheap ass maintence that can be done with small amounts of counterfeit parts for massive profit

if they have like stock rooms for all the parts, then sure, its probobly low incentive. if someone just buys a ship and gets a parts list ANYTHING can happen.

I assume its a service you can buy from who ever, just like calling the electrician from the yellow pages.

i.e. would you think a manager might not try to hire cheaper people if they feel they can get away with it. Like the light bulb guys vs the engine room guys. But sometimes they trespass on each others turf to get the job done and then you can get bad parts running for years before their even looked at by the other crew

you get the cheap guy that are still damn expenisve to do some "non critical work". It turns out there is something they gotta do where they did not think to get the job done. Then your left with either letting them try it, or getting a mad expensive service call to the right guys. Then you possibly just cost money on your gamble. Some people will just say "hey go try it". Especially if he thinks he knows what it is and he happens to have a part that might work in his truck and its friday before a vacation.


I would hope ships are better then this with some more established rules, but it seems like it can happen. Especially if their doing maintence all around the world! the navy can't even get their ships maintence in order and they got the fattest government budget ever and oversight like you would not believe (fat leonard scandal)

if they HAD to go to a particular port for maintence, with a certified company thats like life time involved with the ship, thats good. but you know the maintence may happen near the cape of africa with god knows who. And the ships gonna be loaded with bananas and Australian fancy ass meat, so they will have a gun to the maintence guys head to finish ahead of schedule. Their like truckers, dead line is EVERYTHING. If it was carrying minerals or some shit OK it might get done right but not if its loaded with millions of dollars of perishable goods.

[floobydust]

Are you absolutely certain it was moved to China? The Phoenix Contact website right now says those are manufactured in Turkey, so if you are correct about it having moved to China, then they actually moved it back!

That was the COO paperwork where they are made, it could have moved after the pandemic lockdowns rattled manufacturers over there to leave, or the website is inaccurate.

Aliexpress Phoenix Contact Store lol pic related springs come pre-salted and oxidized! 

You know that's not Phoenix Contact selling there, right? If it's genuine Phoenix Contact product, it's just a reseller.

Yes, I wasn't taking any of the cheap stuff seriously. No brand name or model number, trademark, copyright etc. is sacred unless you register it there before someone else. But the visible oxide is terrible in that pic. ICK.

Wago products are extremely expensive on Digikey. Coincidentally, I actually just placed a big order today directly from Wago. (I also ordered another couple hundred bucks or so of Phoenix Contact stuff from Digikey and Mouser today.)

My employer has an extremely good discount at Wago, so we would pay under USD $0.70 each for 280-681, in a box of 100. List price here is about $1.75 per piece. Given the discounts Wago will give when ordering directly, the $0.50 for a knockoff is extremely unattractive. That tracks with the pricing for AliExpress terminal blocks in general -- they are no bargain, often costing exactly the same as original Wago, Phoenix, or Weidmüller.

I find the German terminal block companies - Phoenix Contact, Wago, Weidmüller are all the same, you go through their rep, their distributors, their dealers etc. in some antique sales ecosystem they have. I wasn't doing the high volume purchasing but it was not direct, ist es verboten- only through distributors. Maybe different in your country?
Purchased through distributors in North America, the prices are similar and overinflated. Weidmüller was several k pieces a year but I don't know who/how we bought them from. There are always parasite middlemen I find adding some fat.

These are dollar parts used in critical infrastructure. Price only was an issue if bidding on lump sum for the panels, most of the cost is labour.
I think it more likely human factors such as bad wiring assembly or damage of the terminal block would be the Mavi issue, as a guess.
Even the ferrule crimp tool, I got in shit for buying the Phoenix Contact 6-point one but the corporate standard was the 4-point ferrule crimper. Who knows why or what, and what works with the Wago's. There seem to be undocumented practices as well. Ferrule tube thickness was also a concern of mine, less copper lower price but how's the crimp?

[johansen]

I cant comment with regard to oil tankers and container ships.

But i can tell you that smaller fishing vessels.. they wont even bother fixing a 2 inch pipe pissing 100 gallons a minute of seawater into the bilge. Its not a big enough leak to spend any man hours at sea fixing, when there is money to be made.

Arguing over whether or not it was a genuine wago part?

The ships are run until they fail, same as cheap cars. People drive them until they break down, preventative maintenance? What's that?

[tooki]

I find the German terminal block companies - Phoenix Contact, Wago, Weidmüller are all the same, you go through their rep, their distributors, their dealers etc. in some antique sales ecosystem they have. I wasn't doing the high volume purchasing but it was not direct, ist es verboten- only through distributors. Maybe different in your country?
Purchased through distributors in North America, the prices are similar and overinflated. Weidmüller was several k pieces a year but I don't know who/how we bought them from. There are always parasite middlemen I find adding some fat.

Generally speaking, companies have been shifting away from the old model of middlemen and official distributors, towards selling directly to their customers. (Not just industrial products, it’s the same with consumer goods.)

Switzerland used to be absolutely dominated by “official distributors”. Nearly every major brand had some local company as the sole importer. Over the years, more and more of the big brands they imported ended up just buying the respective distributor and turning it into the local subsidiary, or simply ending the distribution contract and establishing a new subsidiary.

We certainly aren’t high volume by any stretch of the imagination, but both Wago and Phoenix are happy to sell to us, and I think they will sell to anyone (at minimum, to companies). The big difference I see between the two is that while Wago gives bigger discounts, they generally won’t split packages, so I had to buy way more terminal blocks and accessories than I actually needed, since I have to buy the boxes of 25, 50, or 100. Phoenix has a lot more products you can buy by the piece, but the discounts are more modest. So I buy in bulk directly, but small quantities I get from distributors.

These are dollar parts used in critical infrastructure. Price only was an issue if bidding on lump sum for the panels, most of the cost is labour.
I think it more likely human factors such as bad wiring assembly or damage of the terminal block would be the Mavi issue, as a guess.

Probably. That’s why the industry has been moving steadily to technologies that reduce human labor and error. First from screw to tool-required cage clamp, then to basic push-in, then push-in with plastic button opening, then versions with levers, and now Phoenix’s latest has the clamping mechanism pre-stressed like an armed mousetrap, so even stranded wire without a ferrule can be inserted with no tool at all. The wire hitting the base triggers the mechanism and it snaps shut.

Even the ferrule crimp tool, I got in shit for buying the Phoenix Contact 6-point one but the corporate standard was the 4-point ferrule crimper. Who knows why or what, and what works with the Wago's. There seem to be undocumented practices as well. Ferrule tube thickness was also a concern of mine, less copper lower price but how's the crimp?

Ferrules are pretty standardized, at least from all the brand-name manufacturers. With that said, just to cover my ass, I did buy a Phoenix ferrule crimper and ferrules, since as a system they have UL certification. (I.e. the certification is valid only when those products are used together.) I needed the crimper anyway, so buying a few “certified” ferrules to go with it was no big deal.

But if you look at the specs of the ferrules (which include dimensions), it’s all the same. They just follow the old DIN standards that originally defined these things.

I certainly would not buy no-name ferrules from AliExpress, since their quality is truly unknown. FWIW, I buy mostly Vogt (extremely good prices on these from Reichelt.com, by the way), with some Phoenix and Wago. (I have one set that is Knipex branded, but I’m fairly confident that Vogt is the actual manufacturer of those.)

As for the crimp shape: this is a bit of a sore spot for me, as someone who is a bit of a perfectionist and likes to have the best solution for a given situation. Clearly the existence of multiple shapes has some reason. Otherwise we wouldn’t bother having hex, square, true round, and trapezoid for small wires, and hex, trapezoid, and rectangular-ish for big ones. (And there are likely more I didn’t think of.) Yet whenever I have asked the manufacturers for guidance on when to choose which shape, they all insist it makes no difference. (If you know and are able to share, I’d love to know what the reason is that your employer had settled on the hex crimp.)

My conclusion so far has been that the only reason to choose one over another is to better match the opening the crimped ferrule will eventually go into.

In the end, the only reason I ordered the square crimper was because the trapezoid crimps are slightly wider than square ones, and one size of trapezoid crimp won’t fit into the small (3.5mm wide) terminal blocks, whereas the same size ferrule and wire with a square crimp will do so comfortably. My reasoning was that a square crimp will have more contact area in the fundamentally square spring clamp than a hex crimp. I’ll probably eventually add a hex ferrule crimper for screw terminals with round wire holes (which is what every single user-mounted Swiss mains plug uses inside), too.

In a way I wish someone would make a “mil-spec” ferrule crimper using indent crimper technology and precision. I mean, with my AFM8 indent crimper, I can crimp a ferrule for 4mm2 onto 0.25mm2 (24AWG) wire securely! But of course it’s not fully automatic (in that you have to set the indent depth manually), and in reality you’d need to change the crimp shape, since indents alone would be terrible for this application. (Too little contact area with the strands.) But it’s just a curious exercise in tool precision.


(The lack of manufacturer guidance is similar to when choosing soldering fluxes: ChipQuik has something like 2 dozen different fluxes, many of which have practically identical descriptions, so you have no way to know why you should choose one over another, among the group with similar descriptions. Same thing with MG Chemicals solder wick: multiple versions with identical descriptions. I actually wrote ChipQuik, but of course got no reply at all.)