Helix angle the helix angle. The efficiency can be plotted versus the helix angle for a constant friction, as shown in the adjacent diagram. The maximum efficiency is a helix angle between 40 and 45 degrees, however a reasonable efficiency is achieved above 15°. Due to difficulties in forming the thread, helix angle greater than 30° are rarely used. Moreover, above 30° the friction angle becomes smaller than the helix angle and the nut is no longer self-locking and the mechanical advantage disappears. In helical and worm gears, the helix angle denotes the standard pitch circle unless otherwise specified. Application of the
38 Degrees comes from the speed with which 38 Degrees can launch a campaign or find out members' views. Campaigning techniques include both online methods, such as mass email, social media, blogs and online petitions, and offline methods, such as calling an MP or visiting a surgery. 38 Degrees has also fundraised from its membership to commission legal advice and to run advertising campaigns. 38 Degrees 38 Degrees is a British not-for-profit political-activism organisation. It describes itself as "progressive" and claims to "campaign for fairness, defend rights, promote peace, preserve the planet and deepen democracy in the UK". In October 2013, it