What we’ve been able to find out is that the world-recognised symbol of the Nazi SS (Schutzstaffel) was first worn by the Leibstandarte in 1933. It originated from the “Sig” or “Sigel” or even “Siegel” rune and was part of Hitler’s widespread use of occult symbols.
Runes seem to have exerted a compelling influence on the Nazis and their use can be traced to the occult and völkisch author Guido von List, an important figure in Germanic mysticism. The SS themselves were Heinrich Himmler’s secret agents and ranged from the Gestapo to soldiers of the Waffen SS. The original meaning of the Sigel Symbol represented Victory, Power, Success and Health. Some sources claim it is an ancient sky symbol and represents the power of lightning. Believed by the Nazi’s to be of Nordic origin, the symbol was “corrupted” by the movement as was the Swastika and through their actions changed to mean racial intolerance and death.
A more realistic view is that the Nazi designers were simply seeking Northern Aryan symbols and liked the shaped of the two S-shapes stylised as lightning bolts. This would tie in with there belief in “Blitzkrieg” Lightning Force / war / power”.