# Benefits of Wire Ferrules in the Shop



## CalgaryPT (Sep 20, 2019)

I've had an annoying and reoccurring problem with my Edwards Ironworker (my FAVOURITE shop machine). It would shut down for no reason every once in a while. I know these machines are built for decades of use (even my model which is the smallest they make), so I started with the assumption that it was electrical.

I knew my 220V single phase electrical connections were correct—even though I never had it checked by a pro when I wired it years ago. But I understand this stuff _reasonably_ well. When I once got the telltale smell of insulation and Bakelite I knew where to look. What I noticed was that either the terminal block connection was always coming loose, or there would be heat damage on the insulation close to the (screw) terminal connection.

I'd go inside and retighten the screw terminals that led to the line cord to no avail. It was just puzzling me what was going on because I'd never had such a persistent vibration problem. The stranded 12 gauge I'd used as my line cord kept coming loose, likely due to the vibration of the hydraulic pump. I tried everything: over-torquing the set screw in the terminal block (still came loose); Loctite 290 kept the set screw locked as advertised (wires underneath came loose); solder-tinning the wires (still came loose); and finally a flat heat shrink crimp lug (failed immediately). Then it hit me. The stranded wire—whether tinned or not—was the problem. Tinned copper wire is soft and collapses with vibration unless it has a structure around it. Untinned copper fans out under the set screw and causes heat damage because only half the conductors are functional. A terminal block that allows a "Y" yoke or "Hook" lug would solve the problem too; but some terminal blocks (like mine) only allow the wire itself to be inserted. These are the issue.

The solution proved to be a wire ferrule. If you've never used these before they are great. Sure they make everything look neat and tidy, but they have functional value too. They ensure all the strands in your wire are conductive—which means you've not trying to run 20 amps through only 6 of the 12 strands, for example. They provide a square (or hexagonal) tinned copper surface for the screw terminal to contact tightly, and one that doesn't deform like stranded wire does. But my favourite feature is the tiny serrations on the ferrule left over from the crimping dies. I'm not sure if these are intentional, but they sure help grip the terminal screws—preventing them from coming loose. I guess another feature of ferrules is the insulated jacket that provides some measure of strain relief while ensuring any stray wire strands don't cause a short circuit.

I've only used really tiny ferrules (20-28 gauge) in hobby electronics before, so this was the first time I used them with 12 gauge. I used to think they were gimmicky because they just made everything look so nice. But now I really appreciate their purpose. It's been 6+ months now, and when I was in the shop a few minutes ago I thought, "my ironworker hasn't failed for a long time." So I opened up the electrical box and inspected the connections with the ferrules. They were still tight as ever and there was no evidence of shorting.

WRT crimpers—I'm a huge fan of Knipex tools from Germany. But their version of a front loading ferrule crimper is almost $300 and tough to justify. Even their side loader is $230. Side (lateral) loaders can be found on Amazon for $25 to $35 and work just as well. You only need a front loader for confined cabinet use I think. I used to buy ferrules from places like B&E in Calgary. They sell kits of maybe 6 sizes with 20/size for $35. But now you can find a 1200 piece kit on Amazon for $17, and bundled with a crimper for less than $40. Gotta love that.

Hexagonal crimpers crimp a shape closer to a circle which is good for a lot of smaller terminal blocks. But I've only ever used a square crimper, which works fine in all my applications from hobby electronics to industrial metal working machines now.













Here's a good beginner vid on ferrules:


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## PeterT (Sep 20, 2019)

Cool. Dumb question but once you have made the crimp, what exactly does it plug into? Is that the terminal block you were referring to? Do they have standardized holes that, regardless of wire gage / color ferrule you choose, the metal crimp end will engage in there? Do they just plug in or does a set screw come down on the ferrule?


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## Brent H (Sep 21, 2019)

Hi Peter, 

There are a number of different terminal strips ranging in cable size given what amperage they are designed to hold.  Some have push in spring clip retention, some are set screw onto the wire and others have a clamp type arrangement.

The ferrules that CalgaryPT is talking about should be sized for the wire you are using and also for the terminal strip you intend to put the wire into.  They are super great at preventing the wire from fraying out when you are trying to fit it into the terminal strip which prevents accidentally shorting out the wire next to it and also the ferrule end allows a setscrew type terminal strip to get a good bite on the wire without snipping off little wire strands or twisting up with the wire.

I first used or heard about these things 20 years ago when we replaced the lathe and had to relocate the control box.  It was all done up with these so I sought them out and we redid the controls with the original ferrules.  They are super great!

I recently picked up 2 assorted kits of them at a princess auto in the surplus and bought a nice crimper.


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## CalgaryPT (Sep 21, 2019)

@PeterT here are a few examples from my parts drawers. The silver one in the rear of the first pic is the largest you generally would use common ferrules on. The outside terminals are rated at 60A and the two inside terminals go to car batteries...so several hundred amps. The above video shows another type.

The second pic is a LAC (Linear Actuator Control) board for my RC lawnmower. It is only 1.75" wide so you can imagine how small those ferrules are. I think the wires are either 24 or 26 gauge...so tiny.

As @Brent H correctly points out you must match the ferrule to the wire and the terminal, especially size-wise. Also some terminals are square for square ferrules and some are round for hex ferrules. I've never had a hex crimper—I use square crimps in these and they work just as well. I'm sure they don't take this short cut at Bombardier, but for my stuff it works great. At 24 or 26 gauge I don't think shape is as important as a wire/ferrule combo designed for 60 Amps.

If you look on YouTube the audiophile guys often have high end amplifiers that use wires as thick as welding cables, and these all go into round terminals. They have a trick where they don't crimp the ferrule but instead use heat shrink tubing to hold it in place. Then the set screw mashes the ferrule to its proper shape. Seems wrong to me because you loose the benefits we discussed in this post. So I just don't get that...but whatever.


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## Janger (Sep 22, 2019)

What if you have these old school terminal strips? Screw and wrap around type? Is this still a good idea?


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## Johnwa (Sep 22, 2019)

I found out about ferrules about a year ago.  They work great.  I don’t think they would work well with Janger’s terminal strip.  I’ve switched from that type of strip to the types shown in CalgaryPT’s pictures.


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## PeterT (Sep 22, 2019)

Interesting stuff. Glad it came up in conversation. I always wondered how those blocks in machines & such look so neat & tidy. 

The only heavier gauge stuff I have done is with Anderson power poles, also a crimped affair. But they are intended to be repeatably connected together either wire to wire or mini panels. I kind of standardized on these a while back for my RC gear so I could run multiple chargers, battery warmer, cooling fans, DC-AC converter.... all off a 12V battery source. 
https://powerwerx.com/anderson-power-powerpole-sb-connectors
https://powerwerx.com/anderson-powe...30m!#-!315&pageSize=90&orderBy=0&pageNumber=1
http://www.westmountainradio.com/rigrunner.php


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## Brent H (Sep 22, 2019)

hey Janger, for the older screw type that you show we use either the terminal crimps with the open end or the round end if you don't want them to come free if the screw gets loose.  Typically if it is really important we will solder on the crimp and then heat shrink onto the crimp and wire.  You can heat shrink on adhesive lined heat shrink to make the connection water proof.

For the terminal strip you have pictured we don't wrap around any wires - always a crimp termination.


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## CalgaryPT (Sep 22, 2019)

Janger said:


> What if you have these old school terminal strips? Screw and wrap around type? Is this still a good idea?


I think there is still a place for old school wrap around blocks like you show John. For temporary projects that's fine. Yours remind me of the old Radio Shack ones from the 70s; but I know you can still buy them at Home Depot in the electrical isle. I think guys use them for grounding buses, etc. @PeterT 's comment about RC is bang on. It's vibration that's the issue here, so as a grounding bus where shorts aren't an issue they are a good alternative.

For longer use or if you need to use them in a vibration prone environment, I use old fashioned crimp (top of pic), or crimp & heat shrink (bot of pic) "Y" yoke or circle lugs. You need enough room on the strip to use them though. I know the black type you posted and there isn't much room on them so you may have to use bare wire.

One last note on ferrules. Even though I don't have a  hex ferrule crimper, I have used them. I double checked on Amazon and for smaller electronic work you may be better off with square crimps. Square crimpers like mine go from 10 to 28 AWG. But I can only see most hex crimpers down to 23 (so really 22 gauge) wire. A lot of smaller electronics stuff like Raspberry Pi and Arduino uses 24 gauge or smaller. Seems like it would make more sense for hex to go smaller, but maybe it is the mechanics of the dies. You have to go to the  crazy expensive Knipex to get 28 gauge range.


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## CalgaryPT (Sep 22, 2019)

@Brent H is a mind reader!


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## Brent H (Sep 22, 2019)

LOL.... just following along.

We have tons of vibration and wire issues on the ship so you have to be sure the crimps are strong and the terminals are tight.  We do Megger * testing annually on all the major power circuits each year and typically we also do tug tests on the terminal strips - tighten up anything loose etc.  Most equipment has to have some kind of G force rating and vibration resistance as well.

* Megger testing is a test for insulation failure along wire runs.  Essentially you pump a larger voltage signal down the wire to saturate the insulation and a meter will indicate what the resistance to the over saturation is.  Good wire will come back infinite- no leakage to ground  Bad or failing wire will start reading below 2 Mega Ohms.  (this is a pretty basic description)

Terminal ends keep the wee wires from fraying out and creating shorts or grounds and they also help to ensure the conductor gets all the wire strands working for you properly.


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## Chicken lights (Sep 22, 2019)

I picked up that crimper a couple months ago, I like it 

I crimp, then solder, then heatshrink, I don’t know how proper that is but it works for me


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## YYCHM (Sep 22, 2019)

Have ever seen a bus in a power utility office?  That's one big hunk of copper.  I was impressed to say the least.

The last cruise we were on I discovered that there are literally hundreds of PLC's distributed across the ship.  Must be a nightmare keeping the wiring secured on those things and trouble shooting the system.


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## Dabbler (Sep 23, 2019)

One cruise ship vid I was watching said they had 4000 km of wiring in it. that's nearly coast-to-coast!  That must translate into tens of thousands of connections!  I've noticed that ship wiring (such as on BC Ferries) is of the highest order.  Have to.


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## Brent H (Sep 23, 2019)

It can get very insane at times - lots of wires all over the place....right now I gotta run as it seems one of those wires is causing us an issue clutching in.....argh!


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