Whenever I am setting up leaders and rigs using anything over 100-pound test, I generally use crimps instead of knots to secure my connections, swivels, etc. Crimps are tried and true when done properly and only require a few special tools.
You’ll find several varieties of crimps on the market to choose from including double and single sleeve, aluminum and copper. All of these crimps are secured the same way, but some have specific applications.
Aluminum and copper crimps are both used for mono leaders, but copper is preferred for crimping wire cable due to the corrosion of dissimilar metals.
You will need a crimping tool and there are several types and sizes available. A small pair will work for all crimps, but you will have to squeeze the larger crimps multiple times. A large crimper will work best if you are using leader material that is 200-pound test or more.
It really helps to have mono cutters or some tool to cut the ends of the mono clean so the line will pass through the crimp easily. Smashed or burred ends make it a pain to slide the line into the crimp and will make you assume the crimp isn’t big enough.
To make a good crimp connection, put your mono or cable through the crimp, pass through the eye of the terminal tackle or make a loop and then run the line back through the crimp. Leave the tag end sticking out of the crimp just a little bit. Put the crimp in the appropriate size slot in the jaws of the crimper. Leave a little bit of the crimp sticking out so that when the crimp is squeezed, it will flare out the metal edges to prevent the crimp from cutting into the mono.
Squeeze down with the crimper until it bottoms out or you have a firm squeeze on the metal. The crimp should not crush or deform the crimp. Often you have to change positions and do a second squeeze to cover the entire crimp (except for the ends). The photo below shows what a crimp will look like after you give it the proper amount of squeeze.
You can purchase crimping kits that include a crimping tool, crimps, chaffing tube and everything else you need. This one from Melton’s comes complete with everything you need.