Terminal-Tackle Crimp Strength

Discussion in 'Tackle and Rigging' started by pametfisher, Feb 20, 2010.

  1. pametfisher

    pametfisher Senior Member

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    A couple months ago I posted some data on leader KBS (knotted breaking strength) and Maximum Drag. (Connecting Terminal Tackle) One of the issues that becomes clear is that KBS can start to affect Maximum Drag settings as you drop down in leader strength.

    One of the ways to improve the connection to terminal tackle is to use a small Bimini Twist, the other possibility is to crimp the connection.

    Crimping is its own science, and although many have experience with it, I haven't used crimps and wanted to do some testing. John_Madison CT stepped forward and offered to crimp a few leaders for testing and they arrived early this week.

    John has prepared an excellent package of about 30 crimped leaders using 60# and 80# mono and fluorocarbon, which was about 25 more connections than I was expecting! The crimps look very well made, the packages are well organized and include a variety of leader materials, crimp materials and sizes. Great work John.

    As I test them over the coming week, I will add information into the placeholder replies that follow.

    As a preview of things to come, I've started testing one package:

    Sufix Superior 60# Mono Leader

    ABS: 103 lbs. !
    KBS: 72 lbs. !

    As I've said before, what manufacturers put on the package often bears little relationship to actual strengths.
     

    Attached Files:

  2. pametfisher

    pametfisher Senior Member

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    60# Sufix Superior 0.8mm ABS: 103 lbs. KBS: 73 lbs.; Jinkai J Crimp for 0.74 to 1.00 mm

    Breaking Strength Test of Crimps
    Each leader was loaded in 2.5 lb. increments until the line fractured or the crimp slipped

    Leader 1: 83 lbs. Cloop broke
    Leader 2: 80 lbs. Crimp slipped, loop broke
    Leader 3: 75 lbs. Crimp slipped, mainline broke above crimp
    Leader 4: 70 lbs. Crimp slipped, mainline broke above crimp
    Leader 5: 63 lbs. Crimp slipped, loop broke
    Leader 6: 61 lbs. Crimp slipped, loop broke

    These leaders appear to be well made with crimps that look fully and evenly pressured. The line diameter of 0.8 mm is within the range for Jinkai J crimps.

    The failure mechanism appears to be that the mainline stretches and gets thinner as it is loaded and then the crimp slips and damages either the loop or the mainline immediately above the crimp. The crimp can be felt slipping and the loop is smaller even if it wasn't broken.

    Go to the next post and see the results for the same line, same crimper but smaller K size crimps.
     

  3. pametfisher

    pametfisher Senior Member

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    60# Sufix Superior 0.8mm ABS: 103 lbs. KBS: 73 lbs.; Jinkai K Crimp for 0.52 to 0.62 mm

    Breaking Strength Test of Crimps
    Each leader was loaded in 2.5 lb. increments until the line fractured or the crimp slipped

    Leader 1: 88 lbs. Mainline broke 1/4" above crimp
    Leader 2: 88 lbs. Mainline broke 1/4" above crimp
    Leader 3: 86 lbs. Crimp slipped, loop broke
    Leader 4: 86 lbs. Crimp slipped, mainline broke above crimp
    Leader 5: 93 lbs. Crimp slipped, loop broke
    Leader 6: 87 lbs. Crimp slipped, loop broke

    These leaders appear to be well made with crimps that look fully and evenly pressured. The line diameter of 0.8 mm is larger than specifed for the the range of the Jinkai K crimps. However, the line fit, the crimp seemed much more compressed and the connections were much stronger.

    The failure mechanism appears to be that the mainline stretches and gets thinner as it is loaded and then the crimp slips and damages either the loop or the mainline immediately above the crimp. The crimp can be felt slipping and the loop is smaller even if it wasn't broken. In a couple of cases, the crimp did not slip, samples 1 and 2, but pressure withing the crimp appeared to create a stress point.

    These were very strong, consistent connections.
     
  4. pametfisher

    pametfisher Senior Member

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    60# Sufix Superior 0.8mm ABS: 103 lbs. KBS: 73 lbs.; Bill Fisher 1.00 mm Copper Double Barrel crimps, Note: Crimped at smaller hole on crimper.

    Breaking Strength Test of Crimps
    Each leader was loaded in 2.5 lb. increments until the line fractured or the crimp slipped

    Leader 1: 51 lbs. Mainline broke in crimp
    Leader 2: 56 lbs. Mainline broke in crimp
    Leader 3: 58 lbs. Mainline broke in crimp
    Leader 4: 56 lbs. Mainline broke in crimp
    Leader 5: 53 lbs. Mainline broke in crimp


    These leaders appear to be well made with crimps that look fully and evenly pressured. The line diameter of 0.8 mm seems too small for the 1.0mm crimp.

    The failure mechanism here seemed to be that the crimping process had damaged the mainline inside the crimp.

    As many have advised later in this post, you need the right crimp for the job and this wasn't it. The same line crimped with a Jinkai K crimp, above, was much stronger.
     
  5. pametfisher

    pametfisher Senior Member

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    30
    60# Sufix Superior 0.8mm ABS: 103 lbs. KBS: 73 lbs.; Bill Fisher 1.00 mm Copper Double Barrel crimps, Note: Crimped at larger hole on crimper.

    Breaking Strength Test of Crimps
    The first leader was loaded in 2.5 lb. increments until the line fractured or the crimp slipped. The for #2 through #5 I loaded at 46 lbs. None held.

    Leader 1: 46 lbs. Mainline slipped in crimp
    Leader 2: Mainline slipped in crimp at 46 lbs.
    Leader 3: Mainline slipped in crimp at 46 lbs.
    Leader 4: Mainline slipped in crimp at 46 lbs.
    Leader 5: Mainline slipped in crimp at 46 lbs.


    These leaders appear to be well made with crimps that look fully and evenly pressured. The line diameter of 0.8 mm seems too small for the 1.0mm crimp.

    The failure mechanism here seemed to be that the crimping pressure was insufficient.
     
  6. pametfisher

    pametfisher Senior Member

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  7. pametfisher

    pametfisher Senior Member

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  8. John_Madison CT

    John_Madison CT Senior Member

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    I really look forward to Roger's results. To help minimize issues like crimp pressure, I used the same crimper for all the leaders. It was the Braid Pre-Calibrated crimper.

    What I like about this crimper is that it "clicks" when done. It helps take the guess work out of how much pressure to apply.

    [​IMG]
     
  9. TBaker

    TBaker Senior Member

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    This'll be great! Been crimping 80+ mono and flouro for a long time now and never had one fail, but I've never known how strong they REALLY are. One thing I do know is that on that size line, my crimps are better than my knots! ;)

    Really appreciate you guys doing this! :)
     
  10. Locke N Load

    Locke N Load Wannabe Tuna Fisherman

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    I really look forward to Roger's results. To help minimize issues like crimp pressure, I used the same crimper for all the leaders. It was the Braid Pre-Calibrated crimper.

    What I like about this crimper is that it "clicks" when done. It helps take the guess work out of how much pressure to apply.

    [​IMG]

    I noticed in the last picture, the big one, that the crimping is very close to the edges. I know from learning from others that you need to leave the edges of the crimp untouched so they metal flares and does not pinch the line. My question is do you purposely go that close to the edge or is it just that the crimpers are that wide? My crimpers allow me to leave 2 to 3 times as much room on the edges than in that picture while still squeezing plenty of metal. Should I be going closer to the edges and maximizing crimp contact?
     
  11. John_Madison CT

    John_Madison CT Senior Member

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    I agree that a flare at the end of the crimp is very important. No flare and the edge of the crimp can start to cut the mono.

    Those crimps you mention do have a flare, albeit small. The Braid crimpers are a bit wider than a regular pair like Hi-Seas or Bill Fishers.

    We'll see what Roger's results show. If we find any trends of weaker/stronger, than I'll start making up a few hoping to get to higher crimp strengths.
     
  12. Locke N Load

    Locke N Load Wannabe Tuna Fisherman

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    Results should be very interesing. Especially to me, as my connections are hollow core threading of fluoro and crimps to split rings, no knots.
     
  13. soggy dollars

    soggy dollars Junior member

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    Anticipating the results...
    Thanks guys!
     
  14. John_Madison CT

    John_Madison CT Senior Member

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    C'mon Roger. I'm not sleeping nights waiting for your results.:D
     
  15. brute

    brute Member

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    Jinkai SC3 crimper, about $30.00 only small crimper that has a stop that can be ajusted. It is also narrow enought to leave a flare at the end of the crimp. Tackle Direct
    Angler Center
     
  16. MikeF

    MikeF Senior Member

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    My thoughts on crimping. First one of the items my company calibrates is crimpers for making mil-spec wiring harnesses for things like satellites and other military stuff so I know a good bit about crimps and tools.

    Crimps work by friction period. In order to get a proper crimp you need a good tool, a crimp designed to fit that tool and designed for the diameter and material of the line. If you mix and match you'll get bad results. The least expensive way to make a crimp tool is by displacement; meaning the tool is designed to close to a specific dimension; pressure is a better choice but will not work if you use a crimp made of the wrong material or size. There's nothing wrong with a displacement crimp tool as long as it hasn't worn (that would be hard to do unless you're doing a lot of crimping) and the crimp fits the die.

    The short version is you need to buy your crimps and tools from the same source and make sure you understand the type and diameter of the material it's supposed to fit. Just because the line fits inside the crimp doesn't mean the end product will be any good. And like mentioned above the ends of the crimp should not be inside the die.
     
  17. John_Madison CT

    John_Madison CT Senior Member

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    That's very good information. I hope to work with Roger on crimping "variables" in an attempt to get to 99.99% of ABS.
     
  18. pametfisher

    pametfisher Senior Member

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    See the Second and Third Posts at the Start of the Thread for Detailed Notes


    Today I tested 12 leaders and posted the results near the beginning of the thread. This is a time consuming process, since my method is to increase the load in 2.5 lb. increments from about 40 lbs. until something breaks. Ten lifts per leader, with an average load of about 60 lbs., time 12 leaders means I lifted about 7,200 lbs. this morning!

    It appears from the second set of leaders that a crimp that is well matched to the line and properly pressured with the crimping tool can yield better results that knotting (excluding a Bimini Twist).

    By looking at the 60# Sufix mono, using a K Jinkai crimp:

    ABS is about 103 lbs.
    KBS is about 73 lbs.
    CBS (crimped breaking strength) is about 88 lbs.

    Considering how quickly a crimp can be made, and how consistent the results are in the second batch. Crimping looks like a good skill to be learned. It appears that there is some trial and error involved, which also means that good testing technique must be used.

    Next week I will test more of the leaders. It will be interesting to see what else comes to light.
     
  19. hamptonsurf

    hamptonsurf Senior Member

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    Where did you see the lines breaking? In the crimp, at the loop, on the mainline? Also, have you tested any with a doubled crimp? I've always been curious to see if that was beter or weaker.


    woops, should have read on. thanks!
     
  20. pametfisher

    pametfisher Senior Member

    1,387
    30
    Where did you see the lines breaking? In the crimp, at the loop, on the mainline? Also, have you tested any with a doubled crimp? I've always been curious to see if that was beter or weaker.

    See the Second and Third Posts at the Start of the Thread for Detailed Notes


    Today I tested 12 leaders and posted the results near the beginning of the thread. This is a time consuming process, since my method is to increase the load in 2.5 lb. increments from about 40 lbs. until something breaks. Ten lifts per leader, with an average load of about 60 lbs., time 12 leaders means I lifted about 7,200 lbs. this morning!

    It appears from the second set of leaders that a crimp that is well matched to the line and properly pressured with the crimping tool can yield better results that knotting (excluding a Bimini Twist).

    By looking at the 60# Sufix mono, using a K Jinkai crimp:

    ABS is about 103 lbs.
    KBS is about 73 lbs.
    CBS (crimped breaking strength) is about 88 lbs.

    Considering how quickly a crimp can be made, and how consistent the results are in the second batch. Crimping looks like a good skill to be learned. It appears that there is some trial and error involved, which also means that good testing technique must be used.

    Next week I will test more of the leaders. It will be interesting to see what else comes to light.