Contran Corporation is a holding company whose subsidiaries include Valhi, Inc., who conducts diversified operations in chemicals, and CompX International Inc., who makes ball bearing slides, cabinet locks, and ergonomic computer support systems. Its primary customers are office furniture makers, but its components are also used in vending equipment, electromechanical enclosures, and computers. Contran also has a controlling interest in Keystone Consolidated Industries, a maker of fencing and wire products. Valhi s NL Industries unit, operating through its subsidiary Kronos, is a leading maker of titanium dioxide pigment, which is used to whiten and add opacity to fibers, paper, paint, and plastic. Titanium Metals, a metal producer for the aerospace and other industries, and Waste Control Specialists, operators of a hazardous-waste treatment facility in Texas, also belong to Valhi (who is controlled by Contran). All of Contran s companies are in Dallas.