Data are presented covering the effect of several variables on grinding rate for the electrolytic grinding process. The relative amount of material removal due to electrolysis and due to conventional grinding action was investigated. The Faraday current efficiency of the electrolytic part of the process was found to be near 100 per cent to the extremely high current density of 700 amps per sq in. This is thought to result from the scraping action of the wheel abrasive which prevents passivation of the work anode. Several phenomena of the process are explained on the basis of hydrogen gas pressure in the work-wheel interface. A formula is presented for calculating the hydrogen gas pressure. Equations are proposed for the basic chemical reactions of the process.