There is then no Torsional strain.
"Hertzian Wave Wireless Telegraphy"
John Ambrose Fleming
Hence we see that to make an electron in an ether possessing Torsional elasticity would require creative energy, and when made, the electron cannot destroy itself except by occupying simultaneously the same place as an electron of opposite type.
"Hertzian Wave Wireless Telegraphy"
John Ambrose Fleming
With this in view, your committee decided that threads having their sides at an angle to each other must necessarily more nearly fulfil the first condition than any other form; but what this angle should be must be governed by a variety of considerations, for it is clear that if the two sides start from the same point at the top, the greater the angle contained between them, the greater will be the strength of the bolt; on the other hand, the greater this angle, supposing the apex of the thread to be over the centre of its base, the greater will be the tendency to burst the nut, and the greater the friction between the nut and the bolt, so that if carried to excess the bolt would be broken by Torsional strain rather than by a strain in the direction of its length.
"Modern Machine-Shop Practice, Volumes I and II"
Joshua Rose