I actually don't use many of the crimpers shown in the body of this article, not that they are not okay tools, but as a professional I prefer the crimps made with professional level tools like shown here..
If I am putting my name on a crimp only professional grade tools such as these AMP crimpers will make me happy. Please do not feel you need to run out and buy these, as everyone has their level of quality that will make them happy, mine is obscenely high.
These parallel-action crimp tools are used in the aerospace industry to make certified aerospace quality crimp terminations. They can be re-built and re-calibrated by certified re-builders / re-calibrators and will literally last a lifetime. Each of these tools has made thousands and thousands of crimps and they remain in-spec.
The one on the right crimps blue and red insulated spade and ring terminals and the one on the left crimps yellow insulated spade & ring terminals only.
The gold standard AMP T-Head crimper on the right is part# 59250 and sells new for $1347.00. The one on the left is part # 59239-4 and sells for $671.00. They can often be found used through a re-builder or re-calibration specialist for considerably less money.
Before you can begin to complain about how expensive a DIY/mid grade crimp tool is just think about what the ones I use cost.. (wink)