Hand Stripping of PTFE Insulated Wire
The hand stripping of PTFE (Teflon) insulated wire can be most challenging. The very things that make PTFE desirable in a wire insulation (toughness & ability to run in thin walls with good voltage ratings) work against being easy to strip. Still, there is a relatively inexpensive hand tool that works well. The key is to have a precision blade that cuts most of the way, but not all the way through the insulation and to have mechanism for centering the insulation in the blades.
The tool that I’m familiar with is the Micro-Strip tool from a company called Micro Electronics, Inc. The beauty of this tool is that it has interchangeable alignment guide to center the wire in the blades and interchangeable blades. This combination of interchangeable parts does a couple of important things. First, the alignment guides come in different sizes to allow you to pick the guide that is closest to the maximum insulation OD. Second, the cutting blades are available in a host of precision sizes. This allows you, albeit through a bit of a trial and error process, to use the optimum combination of the alignment guide and cutting blades. A further benefit is that should the blades become damaged or worn out, they can easily be replaced.
A few other comments in passing. There are doubtless other tools that may work just as well as the micro-strip. What needs to be accounted for is that the thinness of the insulation wall requires a precision stripper. It is no accident that the Micro-Strip was originally designed for fiber optic applications. Also, when you are in a hand stripping environment, it is important to recognize that different folks have different levels of hand-eye coordination, manual dexterity, and even hand size. A tool that works very well with one person may not work as well for the next person, so having a couple of different standard tools that work well can help suit individual preferences. Whatever tool(s) you settle on, it is very advisable to have some spares on hand as these tools will wear over time and they are rather inexpensive.