This is the head of the FTZ lug crimper. As you can see it compresses the lug in a circumferential manner (360 degrees) making the entire lug smaller and creating a true cold formed connection between wire and lug. Proper crimps lead to little to no resistance. A poor crimp can be a point of resistance and heat generation.


You can see the die heads have letters marking them. Each of these heads rotates and there are dies for many sizes of lugs.