Red Seal Machinist Practice Exam

What is the meaning of the term “cutting speed” in machining?

1. The speed at which the workpiece is fed into the cutting tool

2. The speed at which the cutting tool moves against the workpiece

3. The maximum speed of the CNC machine

4. The speed of the coolant flow

The correct answer is: The speed at which the cutting tool moves against the workpiece

The term “cutting speed” in machining refers specifically to the speed at which the cutting tool moves against the workpiece. This is a critical parameter because it affects the efficiency of the machining process, the finish of the surface being machined, and the overall tool wear. Cutting speed is typically measured in units such as meters per minute (m/min) or feet per minute (ft/min), and it is calculated based on the diameter of the workpiece being machined and the rotation speed of the spindle. Understanding cutting speed is essential for machinists as it helps in selecting the appropriate feed rates and cutting conditions, ensuring optimal performance and avoiding issues such as overheating or excessive tool wear. The other options refer to different aspects of the machining process. The speed at which the workpiece is fed into the cutting tool pertains to the feed rate, while the maximum speed of the CNC machine relates more to the machine's capabilities rather than the specifics of cutting speed. Lastly, the coolant flow speed is important for maintaining temperature during cutting but does not relate directly to the cutting speed measurement.