In CNC machining and manufacturing, cutting speed is critical to the operation result and has the greatest impact on tool life. Cutting speed is the spindle speed, while it can be regarded as the speed of tool or the work moves at the point of cut. Based on the different workpiece materials and cutting tools, select a proper cutting speed according to the cutting speed chart for different materials.
Cutting speed, also known as surface speed, refers to the speed at the outside edge of the tool as it is cutting. It is measured in surface feet per minute (SFM). Cutting speed is mainly depending on the type of materials and cutting tools, related to their hardness. The harder the material, the slower the cutting speed should be. The higher the hardness of cutting tool or drill, the faster the cutting speed recommended. In addition, the cutter in larger size has greater surface speed when it is turning at the same revolutions per minute as the smaller tool. The relationship (calculation formula) between RPM and Spindle RPM = SFM/Tool Diameter X 3.82 x tooling correction factor.
Here is the chart with the recommended cutting speed for different materials.
1. Materials: cutting speed for aluminum, brass, bronze, cast iron, magnesium, copper, stainless steel, carbon steel, titanium, etc.
2. Machining process: cutting speed for turning, drilling, reaming, and end milling.
3. Please note the table is applicable for high speed steel tooling, when you use carbide tooling, increasing or decreasing the cutting speed based on cutting tool hardness, for example, multiply the listed speeds by a factor of 2 to 4, and the speed should be lower for carbon steel tool.
4. All speeds are in SFM (feet/min).