How does coolant contribute to the machining process?

Coolant plays a vital role in the machining process primarily by increasing the cutting tool's lifespan. When machining metals or other materials, heat is generated due to friction between the cutting tool and the workpiece. Excessive heat can lead to tool wear, diminishing the effectiveness and efficiency of the cutting tool. Coolant helps to dissipate this heat, protecting the tool from thermal damage and wear. By maintaining the temperature at optimal levels, the coolant allows the tool to maintain its cutting edge longer, which enhances the overall machining process and reduces the frequency of tool replacements.

In relation to the other options, while coolant can contribute to a more efficient process, it does not inherently speed up machining or reduce electric consumption. It does provide a cleaning effect by flushing away debris and chips, but this is not its primary contribution to the cutting tool’s longevity. Thus, the most accurate understanding of coolant's role connects directly to extending the lifespan and optimizing the performance of cutting tools in CNC machining.