Highly Reliable Material: made of high quality brass Alloy, 1/2inch (12.7mm) diameter. Selling Method: 50Pcs in one sale. Can be secondary processed and punched through to make your customized items. Precision Processing Technology: Brass balls are polished, rounded and smooth with precise dimensions. It can be plated, drilled, tapped and threaded and other processing. Wide Application: it can be used in machinery, industrial instruments and handicraft DIY, such as valves, sprayers, instrumentation instruments, pressure gauges, water meters, carburetors, electrical fittings, bearings and so on. The product has excellent conductivity and can be used for conductive components or electroplating process. Solid copper balls are wear-resistant enough, rolling friction can reduce the mechanical friction area and thus improve the service life of components. Simple Maintenance: the product performance is stable, corrosion and oxidation resistance, almost no need for maintenance, if you need to maintain can be coated with a small amount of lubricant on it.