The hand taps most commonly employed today are used in conjunction with a machine, e.g. a tapping machine, rather than by hand.
Thus, it is more common to employ a tap with a cutter shape most suitable for the conditions of use than using in sequence, three taps, i.e. the taper tap, plug tap and bottoming tap.
Two kinds of materials of Carbon Steel and High Speed Steel are available.
When ordering, please specify which one.