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Crimping Terminals onto Large Wire

George

Well-known member
I've been making do using a hex crimping die one size smaller to make a tight fit for some time now. Using one size smaller squishes out ugly copper wings when crimped. If I don't select a die one size smaller than the wire size and recrimp the wire will literally fall out.
Please tell me what tool you use for good crimps.
I bought a tool marked for mm2 some time ago and have been using it. Thinking maybe is was metric thing I got a new one marked for AWG today and the hex is exactly the same on both tools. (#4 hex measures the same size as 25)
I'm about to give up and buy the hammer type.
Yes — I've triple checked my lug size and the wire gauge.
My #4 wire measures ø.221" (actually a little large according to specs — ø.2043")
Crimping hex is .302" AF (both tools)
Lug I.D. is ø.28"
 
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BryanValRox

Elite Member
I've been making do using a hex crimping die one size smaller to make a tight fit for some time now. Using one size smaller squishes out ugly copper wings when crimped.
Please tell me what tool you use for good crimps.
I bought a tool marked for mm2 some time ago and have been using it. Thinking maybe is was metric thing I got a new one marked for AWG today and the hex is exactly the same on both tools. (#4 hex measures the same size as 25)
I'm about to give up and buy the hammer type.
Yes — I've triple checked my lug size and the wire gauge.
My #4 wire measures ø.221" (actually a little large according to specs — ø.2043")
Crimping hex is .302" AF (both tools)
Lug I.D. is ø.28"
George what is the specific problem that you are experiencing? Looks like the tool you selected is capable of multiple sizes. I have always found , if the terminals, wire and crimped are of the same gauge it provides a satisfactory crimp.
 

George

Well-known member
@BryanValRox If I choose the #4 die the #4 wire will literally fall out of the lug. I have to select #6 (or 16 metric) die and give it another squeeze. My new AWG marked crimper will even imprint a "4" on the lug.
 

BryanValRox

Elite Member
@BryanValRox If I choose the #4 die the #4 wire will literally fall out of the lug. I have to select #6 (or 16 metric) die and give it another squeeze. My new AWG marked crimper will even imprint a "4" on the lug.
My guess is that something is mis matched or mis marked. Normally, the lug will have little extra room for the proper gauge wire to be inserted.
Would you have pictures of the problem you are experiencing? To have it fall out after crimping, something has to be mismatched., or the crimping tool hasn’t been closed all the way.
 

7426TRISS

Well-known member
The tool that JeffS refers too should crimp anything you need. #8 Awg to 1/0. Anything big you will need a different tool.
# 8 AWG is good for 30 to 50 amps, 1/0 is good for 120 to 175 amp. THHN gives you the highest amp rating .
 

RockDr896

Well-known member
I like the set Oregon linked. Looks like it can work in small places if you had to and has a carry case. I may have to go boon docking, so I had the excuse to do an electrical project!
 

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George

Well-known member
I'm wondering if anyone would measure their #4 hex die for me. Close the dies and measure AF (across flats). As I said both of mine measure .302"
ATdhvaannkcse
After crimping a #4 lug with a #4 die on #4 wire the lug measures .247" inside. Not nearly tight enough for ø.22" wire. In the photo below I had crimped with the wire in the barrel and let it fall out to take another photo.
It's not a big thing to have to re-crimp using the next smaller die but if I'm the only having to do it I must have something wrong.
 

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BryanValRox

Elite Member
I'm wondering if anyone would measure their #4 hex die for me. Close the dies and measure AF (across flats). As I said both of mine measure .302"
ATdhvaannkcse
After crimping a #4 lug with a #4 die on #4 wire the lug measures .247" inside. Not nearly tight enough for ø.22" wire. In the photo below I had crimped with the wire in the barrel and let it fall out to take another photo.
It's not a big thing to have to re-crimp using the next smaller die but if I'm the only having to do it I must have something wrong.
Would you happen to have a scrape piece of normal stranded 4awg vs the welding cable you show in your photo?
Wondering how a test crimp would turn out on stranded cable?
 

George

Well-known member
Would you happen to have a scrape piece of normal stranded 4awg vs the welding cable you show in your photo?
Wondering how a test crimp would turn out on stranded cable?
Worth a try but all I have in regular battery cable is #6.
⏳⌛️
I tried the #6 battery cable with a #6 lug in the 16 metric die with the same or worse results.
I give up. Already bought https://a.co/d/0hqf7dmc
 

George

Well-known member
More information, your picture shows # 4 awg.

The lug for a #6 awg should be 0.312 round, length 0.500

The lug for #4 awg should be 0.360 round, length 0.530
Thanks
Would that specification be OD or ID?
I've tried both thin-wall/cheap metric lugs 25mm^2 and thick-wall/better 4 AWG lugs.
 
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