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Marine Wire Termination - The Tools
PREFACE: This article is long and rather detailed. It is written in two parts and covers crimp tooling, terminal selection, types of terminals and includes plenty of do's & don'ts. The first part covers heat shrink terminals and then goes over insulated terminals.
After writing this article I have had many request to know what tools I actually use. This is about it...
The tools on the left hand side are my primary hand tools. They are:
AMP = Seven tools total - These are all guillotine style tools, jaws come together vertically not like scissors.These tools are for Red, Yellow & Blue insulated/PIDG & "F" type open barrel terminals. These tools are the GOLD STANDARD, cost HUGE money, and usually only do one or two sizes per tool... (ouch!)
Rennsteig = Orange & Blue handle - This is a high quality German made guillotine style tool that I use for red, blue & yellow butt splices. I also have dies for solar MC-4.
Molex = Three tools for pin & socket style connectors either waterproof or non waterproof. I use these for assembling field install waterproof connectors for radar, Espar heaters etc. etc...
Hollingsworth = This is a tool that I modified to use for heat shrink 14-16GA butt splices & brazed barrel heat shrink 14-16GA ring terminals. NOTE: This tool was not designed for heat shrink but in testing out performed my heat shrink specific dies.
Anderson = This is a tool that I use for 10-12GA heat shrink butt splices & brazed barrel heat shrink 10-12GA ring terminals. NOTE: This tool was not designed for heat shrink terminals but in testing out performed my heat shrink specific dies.
Daniels = This is a tool I use for multi-pin plugs that use this type of pin crimp.
PM Hand Tools = A Swedish made parallel style tool I use for crimp solder style PL-259 VHF connectors.
The tools still in packages are tools I use less often or where the specific die information is on the packaging and it is just easier to keep the package. I also did not list any of the mid grade tools. Those are just to $200.00 to $1800.00 tools.......
When you are thinking $50.00 is a lot to spend on a tool consider that that wall contains about $6000.00 worth of crimp tools and dies......
Crimping is a form of wire termination used the world over and is the number one method used. It is used in everything from the automotive market, aerospace, military, NASA, industry and even in nuclear power plants. Done correctly utilizing the proper tools crimping is extremely reliable.
MARINE WIRE TERMINATION
There are a few key points with crimping for the marine environment:
#1 To create a proper cold-formed termination between the terminal and wire
#2 To use tools and terminals that result in consistent & easily repeatable terminations
#3 To use wire and terminals that can handle the marine environment
#4 To produce terminations that don't result in high resistance
#5 To choose terminals that are made from tin plated copper not aluminum
#6 To choose tools that allow for a repeatable crimp before releasing
#7 To use proper technique which will result in a reliable time tested and proven termination
The Good, The Bad & the Ugly of Crimpers
In this photo I have lined up a short selection of wire crimper's. The one on the far left IS NOT A CRIMPER! I only say this because I have witnessed people putting together marine terminations with a pair of PLIERS.
The next crimper, the one with the yellow handles, is a cheap hardware store quality crimper and should only ever be used in an absolute emergency.
The middle tool is a low grade Klein strip & crimp tool though it's not really well suited for much other than crimping non-insulated terminals and stripping wire.
The fourth tool is a good quality DIY grade
crimp tool intended for heat shrink crimp terminals. This one is a CMI product & is a Taiwanese made version of the AMP 55893-1(LINK)
tool and runs considerably less than half the cost. Sadly this AMP tool used to be made in the USA
and apparently no longer is. Even FTZ, a tool I used to sell, that was made in Taiwan, is now "Made in China". The Taiwanese made crimp tools are generally considered a better quality than mainland Chinese tools are.
The CMI version is actually a better quality tool IMHO. This tool is designed specifically for crimping marine or aviation grade heat shrink terminals. The jaws of this crimper are fairly well machined, and wide enough in cross section, to produce a decent quality crimp. This crimper is also of the controlled cycle or ratcheting type and will not release until a proper crimp has been made.
The final crimper shown is another ratcheting type crimper but this one, set up with the jaws shown, is designed for insulated crimp terminals. It makes a "double crimp" for insulated terminals.
Read on for more details on these different crimpers.
NOTE: There is no such thing as a "marine grade" terminal. I refer to "marine grade" only because that is what the retailers tout them as and what most boaters know them as. "Marine Grade" is just a high quality insulated or heat shrink crimp termination. The same terminals are sold into aviation, industry and marine applications. In aviation they are often referred to as aviation grade... The difference with aviation terminals is that they need to meet minimum standards and be crimped with "certified" tools all of which are FAR MORE EXPENSIVE than the average boater is willing to buy. I personally & professionally use aviation certified tools but the ones below will get you you to better than average...
A Good Example of a BAD Crimper
This is an excellent example of a bad crimping and stripping plier. I say plier because I really can't bring myself to calling this a "tool". These hardware store quality crimp-n-strips will deflect, flex and even cut the heat shrink on expensive heat shrink terminals thus defeating the purpose of spending good money on great terminals. The make horrible terminations, meet no standards and you truly get what you pay for.
The biggest worry with el-cheapo crimp tools like this is the lack of pull out tensile strength you can achieve due to the very narrow cross section or thickness of the jaws. They also lack any sort of reliability in repeatable crimping.
The industry standards for determination of termination quality, including the ABYC, NASA, US Military, UL and other standards organizations, is a tensile strength pull test. This tool does not fair well here....
Crimp Tensile Strenght Standards
People ask me all the time, "How do I know if I got a good crimp tool?".
The only way to know is to physically test your crimp terminations with your tool and your terminals. When you find a combination that meets or exceeds MIL-T-7928G then you have an excellent combination. Once you find and have tested all the combinations YOU USE stick with that brand of terminal and tool ALWAYS.
Unfortunately this is the ONLY decent way to properly know your tool is going to result in a termination suitable for holding up to the marine environment.
After many years of testing, and using tens of thousands crimp terminals in the marine environment, I can say without pause that MIL-T-7928G, for me, is the BARE MINIMUM tensile strength I want to achieve. If you are frugal in your tool and terminal choice then you should at the bare minimum strive for UL-486A.
"But RC what about the ABYC E-11 standard?" My 2¢ on the ABYC E-11 tensile strength standard is that it is PATHETIC and you will be a chronic under achiever if you set the bar to the PATHETICALLY LOW ABYC E-11 tensile strength guideline. E-11 is a complete joke in this regard. There I said it.....! (wink)
Please note that I am a current ABYC member/supporter and also an ABYC certified technician. Just because I am an ABYC member and certified tech DOES NOT mean I have to agree with everything. I call it as I see it and the ABYC E-11 TABLE XV - TENSILE TEST VALUES FOR CONNECTIONS is a ridiculously LOW bar to set......
This is a chart I created by comparing all the useful standards for tensile crimp strength. The chart breaks out the varying crimp standards, including the pathetically low ABYC E-11 standard.
It should be pretty easy for any good quality terminal and mid level or better crimp tool to EXCEED MIL-T-7928G.
Crimp Terminals - Optimal to Sub-Optimal
This photo shows a few of the different types of crimp terminals you can purchase. The terminals in the top row are marine grade crimp connectors with built in adhesive lined heat shrink and are the best possible solution, for most applications, to use on a boat.
As I mentioned there is no such a thing as marine grade
terminals but that is what the better quality terminals have become known as. Heat shrink terminals, as seen in the top row, are expensive, but in my opinion almost always well worth it. They are available from manufacturers such as Ancor Products
, AMP, and FTZ
NOTE:When choosing crimp terminals I would urge you to buy from companies with a reputation to uphold and a long history for quality. If you buy from companies such as AMP/Tyco, Molex, FTZ, Burndy, Thomas & Betts (T&B), 3M, Ancor etc. and you will get better quality terminals than the cheap no-name junk that has infiltrated the country over the last 20 years or so.
The second row of connectors are called insulated terminals but are not heat shrinkable. The ring terminals are a what are considered a three-piece terminal and the butt splices are a solid tube with no seam. These terminals stand head and shoulders above the bottom row but keep in mind that they are not sealed connections. As such they are quasi-open to the marine environment. When used in conjunction with UL 1426 tinned marine grade wire these crimp terminals will last a long, long time provided they are not in any direct contact with water, such as in a bilge.
The third row represents Wal*Mart or Harbor Freight quality terminals that should be avoided on a boat. Heck I'd not personally use this crap in a child's tree-fort let alone a boat. Perhaps the biggest issue is that, being of the bottom feeder variety, they tend to vary tremendously in ID and OD and as such it is a crap shoot as to how a crimp will turn out.
A good tip when buying connectors is this; if you can't see through the insulation, it's most likely vinyl, and should really be avoided. The vinyl insulation on this type of connector can and will crack and the raw metal thickness, where the wire meets the connector to be crimped, is very, very weak in comparison to top quality terminals from reputable manufacturers such as those listed above.
I buy my FTZ heat shrink terminals from Sailboatowners.com (LINK)
For non heat shrink insulated terminals I use AMP PIDG Terminals
and buy them where ever I can find the best price. Because they are AMP they are quite expensive so I search around......
Heat Shrink Termination - A Heat Shrink Terminal Crimper
This crimp tool is designed specifically for use with heat shrink terminals. While certainly not a super pro-level tool it is a decent mid-grade or DIY level tool for the money. This tool is far better than using the wrong tool on these expensive terminals.
This tool is designed to not damage the heat shrink and will yield a reliable crimp when used on factory made heat shrink crimp terminals.
This particular tool is made in Taiwan by a company that makes tools for many of the big names. For readers of this site I was able to strike a deal with an importer and I can now sell this tool for $46.95. All purchases of this crimp tool help to keep MarineHowTo.com FREE!!!
Why To Use a Qualtity Tool
This should illustrate why not to use cheap crimp tools. The bottom tool is the CMI controlled cycle heat shrink crimp tool and the top one is a standard $12.00 cut, strip & crimp tool which certainly does none of it's intended uses well at all.
The thicker well machined jaws of the CMI heat shrink crimp tool will yield a significantly thicker crimp band and lead to a better cold formed crimp.
Well Machined Jaw Faces
A smooth well machined jaw surface is important when working with expensive heat shrink terminals. This tool is designed to avoid molesting or damaging the heat shrink where a cheap or incorrect tool will damage it.
WARNING: No crimp tool for heat shrink terminals that I know of will reduce the occasional tear in heat shrink to 0%. You will occasionally tear a heat shrink terminal no matter what heat shrink tool you use. The proper tool for these terminals greatly minimizes the risk but does not entirely eliminate the risk and make it 0%.
Dimple Crimper = Poor Choice
In this photo I have placed a heat shrink terminal into the jaws of a Klein dimple or staking crimper. It certainly does not take a rocket scientist to understand why a dimple crimper should be avoided for use on a heat shrinkable terminal. Once you squeeze the grip the dimple can puncture the expensive protective heat shrink insulation thus rendering the protection you paid for virtually pointless.
NOTE: This Klein cut-strip-crimp tool shows a spot for insulated crimps and also says insulated & non-insulated for the dimple crimp nests. I can not, with a good conscience, recommend anyone using this particular tool, or any crimp tool like this, on heat shrink insulated terminal.
Using a one size fits all, crimp tool will usually not save you any money in the long run.
IMPORTANT: If and when you do use a dimple/staking crimp tool the dimple is ALWAYS MADE OPPOSITE THE SEAM. Always face the seam AWAY from the dimple, not at it, as I have shown.
In this photo I am showing the orientation many folks often use, it is incorrect. Doing this can split the brazed seam and cause the termination to fail at a very low pull out strain. If you must use a dimple type tool the dimple should be be made opposite the seam.
Perhaps the most lacking feature of a dimple or staking crimper is that you lose any sort of strain relief crimping on standard insulated crimps. The entire load is taken by just the crimp barrel.
A double-crimp ratcheting tool is designed to make two crimps, one for strain relief, which has different sized dies, and one for the bare wire crimp. If you are trying to wire a boat to be ABYC compliant, which by the way is not a requirement for a DIY, a dimple or staking crimper would not qualify as the correct tool to use under E-11 for insulated terminals.
Not The Right Tool For The Job....
This is a prime example I came across that illustrates exactly why it is important to use the correct tool for the job.
These expensive heat shrink crimp terminals were destroyed by the installer by using a staking or dimple crimper as opposed to a tool specifically designed for heat shrink terminals like the CMI Controlled Cycle Heat Shrink Tool. These terminals were less than a week old and the split insulation was intentionally hidden from view, but I found them.
Don't Be Fooled By Cheap Connectors
Don't be swayed by a cheap price on crimp connectors. A good quality crimp terminal will be made of tin plated copper, not aluminum. As I mentioned above FTZ, Burndy, T&B, AMP, Molex etc. all make good quality insulated and heat shrink crimp terminals, so you don't necessarily need to buy them at West Marine.
As an example, I buy 100 FTZ Crimp'N Seal adhesive lined yellow ring terminals from my distributor for about $70.00 per 100 so my guess is that you should be able to find them for less or slightly more. West Marine sells 25 Ancor terminals for about $32.00, or about $128.00 per 100.