Shaving Machine for the Throat
Question
Is it permissible to trim a beard and shave the throat with a hair clipper? [The barber claims that there is no clipper that shaves less than 0.7.]
Answer
Shalom and good tidings!
Typically, clippers indeed do not shave down to the skin [number 0], but it is difficult to rely on this.
Therefore, ask the barber to do this: when he places the machine on you, he should only place the stationary part on your skin, not on the moving part. This way, there will certainly be no problem.
[Every machine is composed of a part that does not move — called 'the stationary part' and a part that oscillates quickly and cuts the hair — called 'the moving part'].
Source
Shulchan Aruch, section Yoreh Deah, chapter 181, paragraph 10