Impact crimps are not reliable

[corn18]

I redid my RV system moving the batteries. While I was removing the existing 4/0 battery cables I noticed one of the wires was not tight in the lug. So I gave it a yank and the cable came out. I thought I had redone all my crimps with my Temco hydraulic crimper but must have missed one. So I went in the garage to test some of my redo cables that had impact crimps. I tried to pull out the cable from the lug on 4/0, 2/0 and 2 wires. Every one I could pull out. Some took some twisting and bending of the cable, but they all came out. I tested two of each size and none of them held.

Then I tried to pull out a Temco crimped wire from the lug. That sucker wasn't going anywhere. Beat the wire with a hammer with the lug in a vice and it would not move. Then I cut the crimp in half to look at it. Just one solid mass of copper. I remember reading somewhere that the hydraulic crimpers actually cold weld the whole cable. Compare that to the impact crimps where nothing was cold welded. All the individual strands were still individual.

I will never use an impact crimper and highly recommend no one use an impact crimper. The impact crimps are not reliable.


Impact crimper

Temco hydraulic crimper

 

[DJ252]

When I bought my crimper, there weren't a lot of entry level choices that went to 4/0. I used the AMZCNC 12 ton hydraulic crimper. The device is fine. No leaks etc. and nearly as easy as pumping a grease gun but the dies aren't accurately sized and frequently had to use the next size down on half of the die, to get anything to hold.

 

[PhilFromMaine]

Like I said in another recent solar build post, decent tools will cost you around 100 bucks when you finish your project. I initially bought the impact crimper and came up with the same results as you. I ended up buying the hydraulic crimper that worked okay, but had a tendency for the dies to stick to the crimp.

 

[jlankford]

Good information. Thanks for sharing it.

 

[TitanMike]

When I bought my crimper, there weren't a lot of entry level choices that went to 4/0. I used the AMZCNC 12 ton hydraulic crimper. The device is fine. No leaks etc. and nearly as easy as pumping a grease gun but the dies aren't accurately sized and frequently had to use the next size down on half of the die, to get anything to hold.

I too bought a hydraulic crimper and found I has to use one size down.

Cutting a test crimp revealed a solid copper mass.

Just a guess but perhaps a more robust, plated lug, would not require using smaller die.

Only took one hot connector after a test run for me to invest in a hydraulic crimper.

 

[Heavy Half Ton]

I think it takes practice and testing. I used it exclusively. I used a three pound sledge, and a concrete floor. I did many test crimps using open ended lugs where you can see the wire on the other side, it should look homogeneous, hard to distinguish individual strands.

 

[Blackrock]

I always used the impact crimping tool when I was running a field service truck and if you pay attention it works just fine. We had a big crimping tool at the shop that looked like giant bolt cutters and had changeable inserts in the jaws for different size cable.
It's like anything you do, pay attention and get it right.

 

[nvs4602]

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[Aussieguy]

AND if you got a real good sold vice on your work bench they can be used to do a final ooomph to a suspect, whacked with a hammer crimp job.

use only real solid vices that can take a extension bar on the screw.
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also seen some people make their own hydraulic crimper using a car jack and some scrap steel + the hammer crimper
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if you got access to a 120 ton press... now that's overkill

 

[Aussieguy]

PS... if you got a local West marine store
some stores have a crimper (bolt cutter style) that you can use
they have a good selection of quality marine grade lugs

 

[dangerranger]

My advise has been use a big enough hammer! a 3 lb sledge with the tool sitting on an anvil, and I have not had any come loose. DR

 

[hour]

I too bought a hydraulic crimper and found I has to use one size down.

Cutting a test crimp revealed a solid copper mass.

Just a guess but perhaps a more robust, plated lug, would not require using smaller die.

Only took one hot connector after a test run for me to invest in a hydraulic crimper.

Same deal having to use one size down, did about 20 crimps yesterday and found that my 2/0 needed 1/0 for a perfect crimp. My 4awg needed 6awg, also perfect. Thought I had it nailed down but all of my 6awg and 8awg crimps produced wings. Their appropriate sizes were too loose. No winning on those lol

 

[TitanMike]

Thought I had it nailed down but all of my 6awg and 8awg crimps produced wings. Their appropriate sizes were too loose. No winning on those lol

I found that if I crimped these sizes ising a multi step process the wings were a non-issue.

I start the crimp and only continue until the connector starts to grip the wire. I then release and rotate the partially crimped connectoe 90 degrees then crimp some more. If no wing is forming I'll go for max pressure. Might have to go a third time but usually that amounts to just knocking down a small "fin" for cosmetic reasons. I shrink tube all my wire to connector junctions so minor cosmetic defects are covered.


A note on "hammer crimps", when wiring bus bars or devices with limited clearance to adjacent insulators/separators (like in a Lynx Distributor, etc) a die type crimper that yields a nice "round" crimp is preferred. I've seen hammer crimps that are fatter and sometimes taller than the wire's insulation when completed.

 

[Heavy Half Ton]

My advise has been use a big enough hammer! a 3 lb sledge with the tool sitting on an anvil, and I have not had any come loose. DR

Exactly!

 

[corn18]

This just makes me happy.

 

[Touch racing]

Even with a hydraulic crimper I like to double crimp and do a tug test. When I say double I first crimp with the next size up die. Then crimp with the correct size. And don’t forget to use a heat shrink.

 

[jlankford]

I went searching for the Temco hydraulic crimper in corn18's initial post. I find that there exists both a die and dieless version. Both are available on Amazon. The dieless version is much cheaper. A photo of a cutaway view of a crimped lug with the dieless indent crimp shows the desired solid "cold welded" copper mass - no strands visible.

So which crimper is preferred (I know, you're going the say the more expensive unit), and does the dieless version give acceptable results?

https://www.amazon.com/TEMCo-Hydraulic-Electrical-Terminal-WARRANTY/dp/B0813S6ZT7/

https://www.amazon.com/Hydraulic-TH0006-5-Electrical-Terminal-WARRANTY/dp/B00HJXHX1K/

 

[rk06382]

If you are using 4/0 AWG the a 16 Ton Hydraulic Battery Cable Crimper is the only way to go.

I also purchased Windy Nation 4/0 AWG 10 Feet Black + 10 Feet Red Welding Pure Copper Ultra Flexible Cable.

The hardest part was cutting the cable ends. I had to buy a Southwire Utility Cable Cutter at Lowes because I could not wait on Amazon.


Hydraulic 4/0 Cable crimps.

Example of a bad OEM 6 AWG cable crimp.

Hammer crimp with heat shrink removed.

Repaired with Hydraulic crimped ends.

Cables installed:

 

[Rixthe1]

I use rosin core solder, and a mapp gas torch, works great, every time.

 

[Heavy Half Ton]

If you are using 4/0 AWG the a 16 Ton Hydraulic Battery Cable Crimper is the only way to go.

I also purchased Windy Nation 4/0 AWG 10 Feet Black + 10 Feet Red Welding Pure Copper Ultra Flexible Cable.

The hardest part was cutting the cable ends. I had to buy a Southwire Utility Cable Cutter at Lowes because I could not wait on Amazon.


Hydraulic 4/0 Cable crimps.

Example of a bad OEM 6 AWG cable crimp.

Hammer crimp with heat shrink removed.

Repaired with Hydraulic crimped ends.

Cables installed:

Was the hammer crimp done by a 98 year old woman? The crimp done properly will compress severely and leave an embossed X in the terminal. At least mine does. And there is no way you could pull the terminal off the wire.

You have to have the crimper on a very solid surface and whack it a couple times with a 3 pound sledge.

It’s one very major shortcoming is that it can not be used on a wire in camper, so if you need to crimp a wire that is already installed, you will need the hydraulic one.