What can be easier and more reliable than a screw joint? You can’t answer this question categorically, but while there is no replacement for bolts and screws, learn how to cut a screw properly. You'll need these skills not only for modding, but also in everyday use, for example, when you repair a car.
I can talk about screw cutting for hours. Yes, I’m not joking, they write dissertations about screw cutting, so it’s not easy. I don’t want to tell you about M3 cutting in 2mm plate. The difficulties may emerge while working with solid or sticky materials, when the hole is deep, but it's another website theme. I'll describe to you the easiest methods and review the most common questions. You'll know how to cut a screw, of which diameter you should cut a screw, how to put out broken screwing tap and how to remove a broken drilling tool.
So, let’s begin. Female screw should be cut with a screwing tap, the same is with screws. Screwing tap is like external screw made from hard alloy metal with cutting riffles on it. Screwing taps can be of different size and number. For screw cutting you should use set with two screwing taps, the first is a draft, the second is finishing (it’s at the bottom of the picture). They differ in depth of riffles that you cut in a screw.

Male screw, that is bolts and external screws, are cut with a screw die. Screw die is made from hard alloy metal and looks like screw with cutting riffles.

To cut a screw you should press screwing taps and screw dies into a special tap-wrench. There are lots of tap-wrenches constructions, there are only few at the picture. The size should fit the pressed instrument.