Grade S27 Resistivity(Oµm) 21 Rockwell hardness (HR10/) 61 (196) Voltage drop for pair bush (v) 2.5 Coef of friction (=) 0.27 Wear Value in 50Hrs(mm) 1.50 Rating Current density (A/c?) 10 Allowable peripheral speed(m/s) 70 Pressure in use(kPa) 14.7-19.6 Main Application especially suitable for slip ring of large turbo-genertors We manufacture both graphite raw material and carbon brush finished products.For the detailed grade information and pdf file,please visit