You often see descriptions for hand swagers that talk about a particular tool being suitable for swaging such and such a diameter of wire rope.

Here’s the key point to remember if you’re in the market for a hand swager: 

Swaging tools swage ferrules, not wire rope. 
It is the ferrule that is swaged to the wire by the tool. It’s obvious then that the ferrule must be matched to both the tool and the wire for the swage to work successfully. 
Buying ferrules to match wire is easy because that’s the way they are identified – by wire diameter. But how do you know if the ferrule is a match for the tool? Mostly you can’t tell. Just because the tool compresses the ferrule it doesn’t mean it’s a match or that the ferrule has been correctly swaged. This is because the extent and nature of compression is the critical factor. Too much and you can damage the wire – too little and the wire will pull out. Aside from luck, only a tool and ferrule designed for one another can get it right. 
The sure way is to insist that the tool and the ferrule come from the same manufacturer. 

A sure sign that the tool and the ferrule are a mismatch: 
Flash. Flash is the term used to describe material from the ferrule that compresses outwards – away from the wire – and between the jaws of the swager. This is bad because it prevents the tool jaws from closing properly. (A number of swaging tools on the market have jaws that are designed not to close so as to accommodate flash – avoid them). 
A minor degree of flash can be tolerated but anything of a size that makes you want to remove it means you have a serious mismatch and a swage that is likely to fail under load.
Usually this occurs when the tool die cavity is too small, or conversely, the ferrule too big for the tool. If the tool has multiple die cavities, moving to a larger cavity may eliminate the flash but now you may not get sufficient compression. 

A sure sign that a swaging tool is a general purpose effort and likely to produce unreliable swages: 
a. Jaws that are designed not to close fully 
b. Jaws that are narrow to reduce compression load and allow a wide range of ferrule sizes to be accommodated. 
c. Jaws that press the “waist” or middle section of the ferrule outwards, away from the wire. 
These tools produce ugly swages with an uneven surface alternating between bulges and compressions and of doubtful holding power. (Our own tests show they typically fail at around half the minimum breaking load of the wire).
CLAMP swaging tools and swage ferrules are designed to work in such a way as to eliminate the problems discussed above. 
Our tools and ferrules are designed to compress the entire ferrule inwards around the wire to produce far superior holding power equivalent to that achieved by hydraulic swaging. 
The tools jaws close completely around the ferrule producing a near cylindrical swage without flash. 
CLAMP tools have highly polished die cavities to ensure a smooth finish to the swaged ferrule and eliminate damage to nickel plating when using plated ferrules.  
Our tools jaws are made from alloy tool steel that is hardened and tempered for durability. 
If you're a professional rigger, CLAMP swaging tools and ferrules are designed for you.