Crimping non-insulated quick disconnects / fastons

[Cubdriver]

I'm not disputing your experience, but can only say that mine has been vastly different.  I spent 6 years working at National Semiconductor (from '84~'90), and there was plenty of stuff there that had insulated crimp terminals - among that, things like rinser-dryers that vibrated plenty and etch sink control panels where things would get dissolved by acid splashes.  I can't recall EVER having a connection issue with a crimped terminal in that time, though there may have been some.  Some time after National I spent 12 years with a small company that made industrial microwave and RF generators, and again, we used a fair number of insulated crimp connectors in those applications, too.  No standout issues there, either, so long as things were crimped with decent and correct tooling.  I've seen failures in cars where someone crunched things with a pair of slip joint pliers or some similar hack, but things done with properly fitted ratcheting crimpers have proven reliable from my experience with them.

-Pat

Non insulated crimp terminals are fine.   It is the insulated one I have a lot of hate for.   

Let me explain, I’ve worked in the field of automation and CNC equipment since the 1980’s.   The only crimp type terminals I’ve seen fail consistently are the insulated ones.  It doesn’t matter where the device was built, it is just too easy to have a bad crimp which eventually fails or worse becomes intermittent.   This has happened on machinery built in many countries by different vendors.   Sometimes it is a single connection over a period of time.  Other times I’ve had to reterminate about half the connections in a machine.    So yeah when I see insulated crimps it leaves me feeling like a hack worked on the wiring. 

Now I’d be the first to admit that other connection systems have their issues.   The difference is the problems occur over time while those insulated terminals can cause issues right out of the gate.    By over time I mean 10-20 years

I got one of these a few years ago:

Astro Pneumatic Tool 9477 7-Piece Professional Quick Interchangeable Ratchet Crimping Tool Set

(Attachment Link)

From Amazon; it's currently listed for $66 US and has dies for insulated and uninsulated terminals, among others.  For specialized crimps, I scour the bay of evil and try to find OEM tooling, but for general use the set listed has served me well.  And whoever is saying that crimp terminals are a hack, well, I think that companies like Panduit would disagree.  I've encountered them plenty in industry, and they work well if properly made up.

-Pat

[tooki]

Benta, what is a shroud BTW? Also, any recommendation for reasonable priced tool for non-insulated ones?

I'm sorry, "shroud" is perhaps not the right term. This is what I mean:

The more common term seems to be "sleeve".

Benta, what is a shroud BTW? Also, any recommendation for reasonable priced tool for non-insulated ones?

I'm sorry, "shroud" is perhaps not the right term. This is what I mean:

Those are called 'fully insulated' terminals, at least in my experience.  We used a bunch of them (specified by the customer) in an industrial microwave power supply built by a company where I used to work.

No. He doesn't mean the fully insulated terminals. He means the rubber sleeves that you pull over an uninsulated terminal, like this: https://www.jst.co.uk/products.php?cat=463

use a decent crimper and the joint will be fine,use a crap tool and problem city.If there so unreliable why are they used thought the electrical industry.

They're certainly not used generally in the electrical industry. Open any appliance or professional equipment and look. They are used for "here and now" and " let's just get it done" repairs. And they are crap. Period.

That's demonstrably untrue. While I actually prefer using the uninsulated kind myself, the insulated ones are widely used in production equipment. For example, look at the Pace ADS200:





There they're using insulated crimps for all the ground ring terminals and either uninsulated crimps with soft sleeves, or fully-insulated crimps for the spade terminals on the AC socket. (I can't quite tell.) (Edit: I opened up my Pace ST-75 and it's got the exact same pink terminals on the AC socket, and they're the fully-insulated type.)

[tkamiya]

I never had any luck with non-ratcheting type. 

For electrical work, I have a JIS certified (I bought it in Japan) crimper for non insulated terminals.  It always works superbly.  I also have ratcheted insulated terminal crimper purchased in US.  I don't think this one is rated.  As long as I use the right gauge cable with right terminal, it seem to work just fine.  But it is very sensitive to this good match.  Not so with uninsulated type.

For small electronics, I have about a dozen of Amazon sourced, Chinese crafted, ratchet crimpers.  They work amazingly well.  I won't use it if I were building life depending equipment or a space craft but no one asks me to build those.  For what I do, they do just fine.  I don't have a budget for buying manufacturer specified crimping tool for their particular connectors.  When I was working for a company, I had to buy those "right" ones but for hobby, no, I can't justify it.

I really like the crimpers that crimps 360 degrees for sleeve type terminal contacts.  Connectors and contacts are expensive though.  They seem to make a gas tight connection even with my cheap 360 degree crimper.

I also noticed insulated terminals are almost always less sure on connections.  I would imagine plyable plastic around barrel will prevent anything from applying enough force to cause cold welding.

[eblc1388]

The problem with pre-insulated terminals is that they hide the result of the crimp. This is especially true for cheap, improper terminals, where very thin material is being used to save cost. The only way to be sure is to cutoff the insulation after crimping and look at the result. Do it for a sample size of three. Look out for splitted seam with conductor strands in the middle not being crimped. Wiggle the cable to see if there is any sign of strand movement at the terminal.

The attached photo shows one proper and one cheap no brand terminal crimped by a proper JST tool. They both look good on outside and passed the crude tug test without problem. But the inside told a different story. The bad one will fail quickly after several thermal cycles. So, please satisfy yourself that the crimp is good before using those unbranded terminals in your project or production line.