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
Nambu Type 90 than the Imperial Army's Type 10 for a few good reasons. First, they were made in lower numbers than the Army type. Second, they were usually issued to ships and Naval aircraft and were lost when they were destroyed or sank. Third, Soldiers and Marines who found flare guns on the battlefield often threw them away, as they were not seen as collectable as pistols, rifles, or knives. In Hollywood movies (like "Demolition Man (1993)" and "Waterworld (1995)"), the Type 90 is used erroneously as a stand-in for a futuristic shotgun pistol. Nambu Type 90 The Nambu Type 90 was