I took apart an insulated terminal to show why the crimper is referred to as double crimper. If your non-heat shrink insulated crimps do not have three parts find some that do. AMP calls these terminals PIDG connectors.

The spade gets one crimp (left side of photo) and the strain relief barrel (middle of the photo) gets a second crimp where I have scuffed the metal. The "colored dot" side of the jaws, of the "double" crimper, are the appropriate size for crimping this strain relief barrel. Using the appropriate crimper such as the "double crimper" pictured above will create both crimps in one single motion.

If I were to disassemble a heat shrink connector all you'd see is the heat shrink and the terminal. You'd only have two pieces, not three, hence the term "single crimp" as it only crimps the crimp barrel because there is no strain relief barrel on a heat shrink terminal.

Unfortunately, there are two separate tools because there are two different types of insulated connectors!

One other important thing to consider is the orientation of the terminal. The terminal should always be oriented so the the split in the barrel is facing the top jaw of the double crimper. Just as there is a right and left to the dies there is also a top and bottom..

A finished insulated crimped terminal made with the "Ancor Double Ratcheting Tool". As with adhesive lined heat shrink connectors you should avoid the use of a "dimple crimper" on an insulated terminal. This crimp tool makes an "okay" crimp but not one that is equal to something that would be allowed in the aeronautical world. That being said it still passes the Mil-Spec tensile strength load requirements...

In the sailing & boating community I often find skepticism surrounding crimped terminals so I wanted to do a little experiment to display the strength of a properly executed crimp.

To do this I used the crimp you just saw being made. The wire used is 12ga UL Listed tinned marine grade wire. This photo shows the crimped butt connector holding the entire weight of two of my anchors. The static load here is close to 70 lbs. on that crimped connector.

This picture sums it all up. A well executed crimp is very strong.

I got bored with the excitement level of just two anchors and decided to up the ante & try it with four anchors. Shown here is a Rocna 33, Spade A-80 (16lbs.), Super Max 35 and a Fortress FX-16 (10 Lbs.).

Yes, you read it correctly, that crimped connector is supporting close to 95lbs.

FOR THE FULL CRIMP TOOL SHOOT OUT VISIT MY FORUM AND SEE THE VIDEOS AT THE LINK BELOW:

I was quite impressed by the durability of just the adhesive lined heat shrink tubing.

The heat shrink alone actually held my 10lb Fortress FX-16 anchor just fine. I then tried my 16 lb. Spade A-80 anchor and the connection failed before I could even turn around and get my camera! Still ten pounds is not bad and it should certainly keep any moisture out. Interestingly enough a yellow terminal crimped with the "el-cheapo" crimpers from the first picture held less than ten pounds in my load testing. Based on that the adhesive is stronger than a cheapo pair of crimpers.... Ouch!!

So the failure point is somewhere between 10 and 16 lbs. static load, for just the heat shrink alone.