Motor shaft voltage comparison test between a heavy duty, industrial grade SGSTM shaft grounding systems and a light duty microfilament style shaft grounding device. This test definitively shows that SGSTM shaft grounding systems are far superior to the light duty, microfilament style grounding devices at decreasing motor shaft voltages to well below 3 volts. Consequently, SGSTM shaft grounding devices will eliminate electrically induced motor bearing damage for the long term. SGSTM shaft grounding systems are proven to run for 10 years at 1800rpm on a single brush all the while eliminating electrical bearing damage for the entire wear life of the brush.