crimping lugs causing wings. should i redo?

[DPC]

does someone mind explaining what the technical issue is with wings being formed if their still is a cold weld when looking at the lug cross section?

The wings mean the lug is larger than the die used.
Generally speaking.

Some lugs do that with one brand of die and not others.
I try and avoid those flared lugs because they might be a goofy fit that causes a wig issue.
If you can jam a fine strange cable into a normal lug without giving it a hair cut thats preferred to a bigger lose fitting flare lug.
That's my opinion

Now and then I deal with cables that a weird like 313 mcm DLO, there is a lug for it but a 350 mcm can be crimped on if your careful.
Inspectors don't like that.

Mechanical lugs are always an option...

This is a Servit connector for bonding ( what ever else you use it for is not my business )

 

[jorby]

I took off an offending terminal and cut it in half and the cross section looks great to me. I don't think I'm seeing a good reason to re-do these unless someone has some technical issue to share that could help inform me

View attachment 289024View attachment 289025

Perhaps it is just the angle in the photo, but it looks like the dies are not aligned. That can cause the edges of the die that are shifted toward the center, to dig in and form wings. The crimp is still good though.

 

[WorldwideDave]

I am wiring my system for my camper van and after a few crimps I decided to research why I am getting wings when crimping my lugs. I am using temco wire, lugs and crimper so I was expecting not to have any problems with this. Most threads suggested I have a cheap crimper or lugs but with everything from temco I expect that not to be the case. For the larger lugs (2/0 for battery, inverter) those seem to crimp fine but the smaller ones (4-6 AWG so far) have had trouble with wings.

For my remaining lugs I plan on crimping half way - then rotating the lug and finishing the crimp to help prevent this issue. I have also tried the die a half size up for crimps but that was too large.

Is this enough of a problem that I should buy more wire and lugs (if needed) and start over? I don't have enough on hand to re-do these if it is necessary. At a minimum I plan on adding these lugs as something to check as I do my routine checks looking at terminal torque

Were you asking about the 'wings' in response to my thread about the wires that failed (had a wing crimp on it) that I posted the photos for yesterday, or just a coincidence ?

 

[rillweed]

Were you asking about the 'wings' in response to my thread about the wires that failed (had a wing crimp on it) that I posted the photos for yesterday, or just a coincidence ?

It is unrelated, but do you mind sharing a link?

 

[WorldwideDave]

It is unrelated, but do you mind sharing a link?

Sure. You can skip words and just look at pretty pictures. Especially page 2's I think where I tore into them.

Thread 'Melted wires between BMS and cells!'

Mar 28, 2025

I created 2/0 AWG sized conductors with 1/4” tinned copper lug on one end and 3/8” on the other end using my temco hydraulic crimper. I replaced the conductors coming off the BMS and heading to the Victron smart shunt. On the positive side I replaced the 2 in 1 silicone wire that came with my battery also with 2/0 AWG. I have been having zero issues.

Today I decided to turn off my PV disconnects and a/c to D/c charger and see what max amps I could pull. I was able to get between 150-160A load no problem with pool pump on max speed. I’ve done this test a few times. I figured it would take...

• WorldwideDave
• Replies: 112
• Forum: Up in smoke... learn from my mistake!

• 
• 

 

[rhino]

Also remember the "size" of the lug is the internal size of the lug to fit a specific wire gauge which is also standardized. What is not standardized is how thick that lug is. So you can use 4 AWG die on one 4 AWG lug and get no wings and get large wings on another brand 4 AWG lug. That is why people are saying you have to test the lug and for the thicker lugs ones you have to use a + size of even one size larger die then use the regular die size. That will help prevent the wings from forming.

 

[WorldwideDave]

Also remember the "size" of the lug is the internal size of the lug to fit a specific wire gauge which is also standardized. What is not standardized is how thick that lug is. So you can use 4 AWG die on one 4 AWG lug and get no wings and get large wings on another brand 4 AWG lug. That is why people are saying you have to test the lug and for the thicker lugs ones you have to use a + size of even one size larger die then use the regular die size. That will help prevent the wings from forming.

Excellent point being made here. But original poster said all same brand - temco crimper, temco wire, temco lugs, so not sure the issue.

I have seen exactly what he is experiencing, though. Some wire just appears thinner than it says on the outside. Some lugs appear larger and some appear smaller. Some lugs thicker and others thinner depending on brand for sure - same with wire.

The last 15 orders on amazon I've made for lugs were all selterm except for some temco because they would arrive faster. I've bought the ANCOR brand from West marine as well.

I've made 47 orders for wires on amazon (yikes!), and of the ones that weren't ones I crimped (like MC4 wires with the terminals already), I've bought from Selterm, WNI, WindyNation (now WNI?), but never temco. At west marine, I've bought the ANCOR ones as well.

I will keep track going forward which ones seem to match up better. I am certain I am using the right crimps, right angles, no error on the crimping side, but I have seen those 'wings' a few times in my crimping in the past 6 months. Once covered with shrink wrap and installed, I just haven't cared too much. It has always been on smaller gauge like AWG 4, AWG 6...not the AWG 2, 1/0, 2/0 or 4/0 stuff I've done. I want to know the combination now that someone has posted about it. Just don't have a lot of DC wire around. Will soon - doing an RV project in a month or two.

 

[robbob2112]

Many in electrical trades are perfectionist and want it pretty. But if complete cold weld with proper cross section is achieved, this defect is only aesthetic. Shouldn't affect performance at all.

Some of us not in the trade are also perfectionist -- little things like wings drive me nuts...


My concern with wings is if they weaken the lug shell that is supposed to be compressed into a circle and if there is vibration it open up if you clip the wings off...

So I would try to avoid them by progressive crimping --- or different dies, etc...

If you do get wings rather than clip them off I would rotate the lug 60 degrees and crimp again -- press the copper back in ...

If there is total fill, the right dies, the right lugs and cold weld they shouldn't happen in the first place...

my preferred lug brands in order are Temco, Ancor, Panduit, and Selterm ....

Used to me Windy Nation was my favorite wire -- but a few problems with it -
My last batch had a discolored streak the length of the cable and when they wound it off the original real they twisted it like a corkscrew several places in the middle.... When I contacted them about both issues they refused to do anything

The discolored streak was about 1/4" wide and maybe 5 strands deep into the copper - Seemed like it might have been a strip of acidic paper the length or maybe some other defect caused when it was made -- Windy nation says ignore it, no problem so that is what I am doing but I am not happy about it ... this was in several different sizes...

Just a technicality but the Windy Nation wire isn't UL listed - for my purposes doesn't matter, but could cause an inspection failure for those that need it.... the inspector would have to be a stickler to fail it... And most welding wire isn't UL listed -- there are a couple but usually with a yellow or orange sheath

So, my last wire order was to 'wire and cable your way' -- DLO wire which is UL listed but is less flexible than the rubberized sheath on the windy nation ...

 

[WorldwideDave]

So, my last wire order was to 'wire and cable your way' -- DLO wire which is UL listed but is less flexible than the rubberized sheath on the windy nation ...

DLO as in diesel locomotive cable?

 

[robbob2112]

Yep, that is the stuff -- It is very fine wire similar to welding wire, but UL listed and has a very tough sheath on it. Impervious to just about any chemical or damage

 

[doing it different]

An hydraulic hose crimper work extremely well, and is my preferred method. But no good for when it's in a tight spot.

 

[Skypower]

If you do get wings rather than clip them off I would rotate the lug 60 degrees and crimp again -- press the copper back in ...

Rob, I usually agree with what you’ve said, but in my minds eye, re-indexing and re-crimping is a bad idea. I have no definitive proof, yet here’s my thinking. When you crimp, the cross section looks like a somewhat flattened hex. During the crimping process the copper flows into the center and around the strands. Once that is achieved, the excess material will flow longitudinally(the length of the lug). If you re-index, you are just reshaping the hex and very little new force is applied into the stands unless the “wings” have a lot of volume. You may even feel when crimping as the handle moves effortlessly until the dies suddenly bottom out.

There might be a way to check this out with the use of an internal resistance meter. Years ago I ran some tests crimping lugs and different treatment was indeed measurable. Simple things like keeping the strands straight and not random in the lug to polishing the dull oxidized tinned finish inside the lug with a few twists of Scotch bright. Does it make a difference? I have two batteries on a middle shelf with the same length of 2/0 windynation and Selterm lugs. The floor batteries have the same cable and lugs but the round trip distance is 3 feet longer yet the measured overall resistance is actually slightly less, only because of the extra attention X’s four lugs.

The new test would be simple. Do a crimp, measure the resistance, re-index and crimp again, then measure again. The test could even include “wings” in addition tests. You have to have lugs on both ends of a short piece of cable because it’s unreliable to read resistance on strands. I’d do this myself but I have restrictions on weight/force on my arms due to surgery.

 

[WorldwideDave]

I almost wish there was a pressure gauge on the side of the crimper and some recommendation on when to stop. I really think the wings are partially caused because I am over tightening them. I have the crimper on the table and I sit in a chair and essentially pull the arm down on the crimper. I do not stand up and push down on it. I believe I am still putting thousands of pounds of pressure on those lugs.

 

[WorldwideDave]

This weekend I’m going to pull out any of my spare conductors that have logs with wings and do some tests. I know where they are, but I just can’t get to them right now.

 

[robbob2112]

Rob, I usually agree with what you’ve said, but in my minds eye, re-indexing and re-crimping is a bad idea. I have no definitive proof, yet here’s my thinking. When you crimp, the cross section looks like a somewhat flattened hex. During the crimping process the copper flows into the center and around the strands. Once that is achieved, the excess material will flow longitudinally(the length of the lug). If you re-index, you are just reshaping the hex and very little new force is applied into the stands unless the “wings” have a lot of volume. You may even feel when crimping as the handle moves effortlessly until the dies suddenly bottom out.

There might be a way to check this out with the use of an internal resistance meter. Years ago I ran some tests crimping lugs and different treatment was indeed measurable. Simple things like keeping the strands straight and not random in the lug to polishing the dull oxidized tinned finish inside the lug with a few twists of Scotch bright. Does it make a difference? I have two batteries on a middle shelf with the same length of 2/0 windynation and Selterm lugs. The floor batteries have the same cable and lugs but the round trip distance is 3 feet longer yet the measured overall resistance is actually slightly less, only because of the extra attention X’s four lugs.

The new test would be simple. Do a crimp, measure the resistance, re-index and crimp again, then measure again. The test could even include “wings” in addition tests. You have to have lugs on both ends of a short piece of cable because it’s unreliable to read resistance on strands. I’d do this myself but I have restrictions on weight/force on my arms due to surgery.

I agree the copper will squeeze out both ends... but when you rotate and re-crimp that is adding more material that will cause it to squeeze out more.


I can test that easy enough with the YR-1035 -- I just have to find a combination of lugs/wire/dies that make wings -- I seldom run into them using the quality lugs/wire.

 

[WorldwideDave]

Well, on the subject of crimpers… Anyone know if they make a bracket to hold that temco one stable?

 

[Skypower]

Well, on the subject of crimpers… Anyone know if they make a bracket to hold that temco one stable?

Nope.
That’s always been a problem with the sloppy raw cast channel type body. I think the same company makes the body for a dozen different clones. The only difference is paint color between them. The dies always want to bypass or rock. I typically bring the dies in contact with the lug and push the dies even before sealing the deal.

 

[Skypower]

Well, on the subject of crimpers… Anyone know if they make a bracket to hold that temco one stable?

You did manage to get me thinking. I might drill and ream for 1/4” hardened dowel pin through both halves, then ream one half for slip fit. Probably only on the sizes I use the most like 4/0, 2/0 , 2, 4 & 6AWG But it’ll have to wait a few months.

 

[HRTKD]

Like the OP I have all TEMCo. Cable, lugs, crimper and heat shrink. When I first started I got small wings - smaller than most of the pictures in the thread. The solution was to switch to a different die. I don't remember which gauge cable I had this problem on but I think it was 6 awg.

Small wings don't bother me. I don't touch them up. I wouldn't try to grind/cut them off. I use heat shrink to cover up the wings. Out of sight, out of mind. As far as anyone looking at my system, all the crimps are beautiful.

 

[Nobodybusiness]

Try 1 + die and one 4awg

Hell if that happens, which it does sometimes with various lugs, I just rotate and crush the wings back into the crimp then cover with shrink tube anyway.

Sometimes you just don’t have the right die.
If the lug fits the wire then just crimp and go..