6 AWG Crimp Lug Anarchy

[Gabe_nyc]

I need to crimp some Ancor 6 AWG lugs onto Ancor 6 AWG wire.

I want to use the crimper in the picture which is from Harbor Freight (but also available from other places).

I have a full set of hex dies with it from #0-10. 

The die marked #6 seems small. Has anybody used this, and if so, which die worked for you.

Alternately, when crimping #6 gauge lugs, what should be dimension across the flats when finished? 

 

[SimonGH]

I think it's a bit more complicated by the type of lug used, since some are thicker than others.

I have the same tool, but mine are just labeled 0-10 with no "AWG". 

Ultimately you have to experiment.

good information here, but ultimately they don't like that tool.  But I think you can make it work.  The alternative is find a west marine - they have a crimp tool in the shop you can use for free (that's what I ultimately did)

https://marinehowto.com/making-your-own-battery-cables/

 

[Gabe_nyc]

I think it's a bit more complicated by the type of lug used, since some are thicker than others.

I have the same tool, but mine are just labeled 0-10 with no "AWG". 

Ultimately you have to experiment.

The lugs and the wire are labeled 6 AWG but the crimp dies are only 0-10 so I am not making any assumptions.

I looked on the Ancor site and did not see any dimensions for their dies. If nobody here has the answer, I plan to call Ancor and find the dimension across the flats on their die. (Of course, I will post it here.)

Experimenting is normally good, but I need to make 3 crimps and only have 4 lugs available. My “sample size” for the experiment would be very meager :-(

 

[longy]

I have never seen any specs for a finished crimp. I doubt any is possible given the absence of spec for the lugs.

 

[Gabe_nyc]

I have never seen any specs for a finished crimp. I doubt any is possible given the absence of spec for the lugs.

I appreciate that there are many variables involved but there has to be at least some sort of baseline number.

I don’t think that a manufacturer can require that ONLY their hex crimper can be used.

I just spoke to Ancor Tech Support but they had neither the information available, nor a crimped lug that somebody could measure. The rep was very nice but not overly encouraging and said that an actual dimension might take as long as “a month.”

I thought that buying brand-name products from a USA (WI) company was a good and prudent way to go, but I might have to rethink that ...

 

[SimonGH]

did you look at the website link I provided?  I think they gave some pretty good info, or at least what a "good" crimp should look like...

also you can clearly see the "AWG" in the picture where you're holding the dies around the lug...

Based on the experience they described in the website link, I would say start 2-3 sizes bigger than the 6 and see if you get a good looking crimp.

Ultimately this isn't an exact science.  You need a sufficient crimp to hold tightly but not so tight that it starts breaking the wire strands.  The following gives a very good overview of all the crimping you could ever want (including the battery lugs).  Ultimately it says #6 should resist 100 lbf for normal spec, and 300 lbf for mil-spec.

https://media.digikey.com/pdf/data sheets/molex pdfs/tbo quality crimp handbook.pdf

I think the other issue you're running into is that every crimp shape is different - each tool produces a different profile.  Some are true Hex, others just squeeze either side (like the harbor freight tool), and some even dimple the middle.  All of it is covered in this manual, but it doesn't seem like there are any general go/no-go dimensions.  From what i've seen, any go/no-go dimensions are supplied with the tool itself (if it's a calibrated tool).  Unfortunately the $59 harbor freight special isn't a calibrated tool.  So if you want exact, then you have to spend $1000 for a calibrated tool.  That's because the tool maker then does lots of tests and basically determines the correct resulting dimensions needed to achieve the pull out specification.

If you really want to be scientific, you crimp the extra lug with the tool and create the best looking crimp you think will work.  Then you figure out how to hang 100 lbs from the wire and see if it separates.

 

[Diarmuid]

I appreciate that there are many variables involved but there has to be at least some sort of baseline number.

I don’t think that a manufacturer can require that ONLY their hex crimper can be used.

I just spoke to Ancor Tech Support but they had neither the information available, nor a crimped lug that somebody could measure. The rep was very nice but not overly encouraging and said that an actual dimension might take as long as “a month.”

I thought that buying brand-name products from a USA (WI) company was a good and prudent way to go, but I might have to rethink that ...

You can't fairly expect Ancor to warranty swages made with a (non-Ancor) Harbor Freight crimper. There are massive liabilities in play. Ancor no doubt views their connections as a system, from wires to terminals to tooling to the training of the person who squeezes the handles. 

If you wish to use your own tooling and perform your own non-certified crimps at home, great! It's what I'd do. But that means you are also your own QA department.  Buy a couple more of the same lugs, make some crimps, and pull-test them to your own satisfaction. Maybe heat-cycle them with a torch a few dozen times. 

 

[SimonGH]

I found this:

https://www.cable-glands-cable-cleats-crimping-tools.co.uk/BS7609-BS7727-British-Standards.htm

6 AWG = 16mm2

Not sure if this is totally right since these look dimpled as well and crimped.  But probably a good starting point.

 

[DDW]

I thought that buying brand-name products from a USA (WI) company was a good and prudent way to go, but I might have to rethink that ...

When you bought that crimper from Harbor Freight did you really think it was a quality tool made in the USA?

A quality crimper made in the PRC is around $200. A quality crimper made in the USA is around $800. 

 

[SimonGH]

When you bought that crimper from Harbor Freight did you really think it was a quality tool made in the USA?

A quality crimper made in the PRC is around $200. A quality crimper made in the USA is around $800. 

^^ this is correct.

I think the reference is to the Ancor wire and lugs.  I appreciate that they could just say "final lug size should be xx mm".  However just from a few minutes of google searching, there are so many different crimp shapes that it becomes a very complicated mess.  So ultimately the specifications are based around destructive tensile testing.

 

[SloopJonB]

Am I missing something here?

When I had to re-do the battery cables on my boat I simply bought the lugs that fit snugly on my cable and crimped them with my swaging tool - big bolt cutter style Nicopress "pliers". 

Don't those lugs only fit one size of wire each?

 

[SimonGH]

Am I missing something here?

When I had to re-do the battery cables on my boat I simply bought the lugs that fit snugly on my cable and crimped them with my swaging tool - big bolt cutter style Nicopress "pliers". 

Don't those lugs only fit one size of wire each?

Yes.  I think the issue is that the hydraulic crimpers he wants to use have a lot more variables.  Multiple die sizes, plus how much you actually crimp.  So it's easy to over/under crimp with them unless you know what you're doing.

I will say my new boat suffered an under crimp on the primary ground to the engine.  So even the production guys get it wrong.  That was a $5 fix that took almost $3000 in warranty effort to find and rectify! 

 

[Zonker]

I'm a bad person. I've done crimps with vise grips, gradually tightening adjustment screw and squeezing. Totally bad idea but when covered with heat shrink tubing they look the same as a proper one. I did have to shorten one cable once and cut off the lug with a dremel and looked inside. Looked very compressed but probably not as airtight as a hydraulic tool. Was it really stuck on? Yes, and I think it did have lots of contact area with the lug/wire interface. I've also used the hand nicropress tool you use a wrench to tighten slowly. 

 

[Diarmuid]

Am I missing something here?

When I had to re-do the battery cables on my boat I simply bought the lugs that fit snugly on my cable and crimped them with my swaging tool - big bolt cutter style Nicopress "pliers". 

Don't those lugs only fit one size of wire each?

It's somewhat the difference between a crimp and a swage (swedge). A crimp is generally less symmetrical and a small one can be done with a pair of fencing pliers in non-critical applications. A swage does not flatten the join but rather reduces it cylindrically using wire-specific dies. The best swagers, like those used on standing rigging, use rollers to get even compression.

A solid crimp should be good enuf for most electrical cabling needs. Except: you get a bit more water/corrosion in them, heat cycling can loosen the wire, and a hard pull on the cable (sliding battery box, something heavy landing on the wire) may be more likely to fail if crimped vs. swaged.

I use a lot of mechanical terminals in our home DC system. They are reliable and easy to snug up periodically. Not sure they are suitable to a bouncing boat, tho. Likewise solder joints: commercial applications often drop a measured solder pellet into the lug, crimp (optional), then heat the lug to fuse and exclude water/air. But solder creates a hard point subject to fatigue in vehicles.

 

[Gabe_nyc]

Several of you raised valid questions.

I have worked in broadcast for a long time and spent much time around connector specs, crimp tools, pull tests etc (although much smaller stuff than #6 ga).

I appreciate both the “system” aspect of this and the liability issues concerned. I was NOT asking them to warranty anything.

ALL I asked for, is what was the dimension of the finished lug across the flats. The tech support guy did say that their 2-sided tool leaves “ears” so this would introduce a degree of “fudge factor” but I think that this measurement would be a good starting point. I was surprised that it was seemingly unavailable.

—

My plan now is to start with a larger size and work my way down. If it appears funky I might just solder it and use double layers of heat shrink for strain relief at the discontinuity.

Alas, though I am in a large port city, it is not very “boat-y” and I cannot just run down to Fisheries Supply or similar -)

—

Simon, I have not looked at MarineHowTo because I’ve been on a phone all morning. I know the site because I have a Universal engine -)

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I am not sure what the price of the Harbor Freight tool has to do with anything. An expensive, higher-quality tool would last for many thousands of crimps, and its dimensions would be guaranteed to be accurate.

With my cheap tool, I don’t need for it to make more than 30 crimps in 10 years (if that). I am willing to measure the resulting size of the crimp and decide if I am happy with it.

In any case, a .312” hex crimp is a .312” hex crimp regardless of if it was made with an $800 tool, a Vise Grip or anything in between.

—

This current project is for a 30-ft sailboat called “Better Angel” but I also own a boat called “TLAR”. Those of you who deal w lot of TLAs and FLAs may find that funny -)

 

[Gabe_nyc]

TLA = Three-Letter Acronym 

FLA = Four-Letter Acronym

TLAR = That Looks About Right

(My “TLAR” was a damaged 20-ft catamaran that I am (very slowly) turning into a powerboat of some kind. There is a thread on SA called “Ditch the Rig” about several such projects.)

 

[El Borracho]

Given all the variables I would think the pull test (100 lbf for AWG 6) would be much better than a dimension-based test. I suspect even the mechanical size, strand fineness, and ductility would be a significant variables.

 

[SimonGH]

I am only looking at the resulting crimps, but from the images on the Marinehowto site the more expensive tool produces more of a swage (compression around the entire fitting) than the crimp you get with the harbor freight hydraulic.  With the HF tool, even though the mandrels are hex shape, you'll find that resulting crimp will not be uniform in shape as material squeezes out between the dies.  But it will do the job.  I've even used it to crimp the ferrule fittings on big galvanized cable for my kid's zip line.

The good news is that you can use the same tool for those nice wire railings people are using on their home decks - the #4 is perfect for the turnbuckle fittings.

 

[Son of Hans]

I used that exact tool and that exact wire, going by the number on the die.  It worked fine.

Those lugs too.