The Bureau of Mines investigated electrolytic techniques for preparing diborides of the group IVB metals. Tib2, zrb2, and hfb2 were electrodeposited from their respective oxides dissolved in borate-chloride-cryolite electrolytes. Titanium diboride was also electrodeposited from rutile (tio2) dissolved in a na2b4o7-na2co3- na3alf6-nacl electrolyte at 1,050 deg c; 14 kw-hr were required to produce 1 pound of tib2. Major impurities in the tib2 produced in a 10-deposition cycle experiment, in weight-percent, were a1, 0.2; Cr, 0.3; Fe, 0.1; V, 0.3; C, 1.4; and o, 1.0. Zirconium diboride was electrodeposited from zircon (zrsio4) dissolved in a na2b4o7-naoh- na3alf6xdacl-naf electrolyte at 1,050 deg c. The zrb2 produced in a 10-deposition cycle experiment contained the following impurities in weight-percent: fe, 0.1; Si, 0.5; C, 0.3; and o, 0.6. Energy required to produce 1 pound of zrb2 was 9.3 Kw-hr.