Cylindricity is the main indicator to measure the straightness and roundness of the bar. The brittleness of cemented carbide rods is relatively high, so the control of cylindricity is more stringent for the process.

The main processing method of cemented carbide bars is centerless grinding. The centerless grinding process consists of three parts: grinding wheel, adjustment wheel and workpiece support (bracket). The grinding wheel performs the grinding, the adjustment wheel controls the rotation of the workpiece, and the workpiece holder supports the workpiece during grinding. There are many ways to match these three parts, and the working principles are the same.

The cylindricity of cemented carbide bars is mainly affected by the center height of the workpiece, the amount of feed, the feed speed, and the rotation speed of the guide wheel in the centerless grinding process. In the process of centerless grinding, the appropriate center height is beneficial to improve the cylindricity of the cemented carbide bar; if the production cost allows, reducing the feed amount and increasing the number of grinding passes are also beneficial to the improvement of the cylindricity. Plastic deformation of cemented carbide bars by hot pressing can also improve cylindricity.