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
Allied Masonic Degrees Allied Masonic Degrees The Allied Masonic Degrees (AMD) are a series of Masonic degrees conferred by "Councils of the Allied Masonic Degrees". The Allied Masonic Degrees form an appendant order of Freemasonry that exists in some Masonic jurisdictions; its degrees are conferred only by invitation. Councils of the Allied Masonic Degrees exist in Great Britain, the United States, Canada, France and Australia and their members also educate one another by presenting research papers on Freemasonry. The structure is very like that of the craft lodges, with the exception that the offices of Secretary and Treasurer may be combined in some