Very confusing dimensions !!

In the description of the title has a length of 15 cm is given! The diameter (screwed together) should then be 4.8 mm! If I count correctly, then results from 150 mm L / 3,14 a diameter of 47.7 mm and not 4,8 mm! Helpful would be an indication of the strength of screws in order to know whether the holes of the keys are large enough to push them over the threaded screw can. Since I assume that I have the information interpreted so right, I'm going to this Order. Keep your fingers crossed!