High-Feed Milling Principles
High-Feed Milling (HFM) is an efficient and cost-effective machining process for milling operations. It is based on the principle of using a smaller cutter diameter combined with high radial depths of cut and high tool engagement angles. The advantages of HFM are significant, including improved tool life, more efficient cutting, better machining accuracy, higher surface finish machining, and more efficient chip removal.
HFM introduces a new approach to machining that is significantly different than conventional milling operations. With the conventional milling process, the tool revolutions are kept to a minimum and tool depths of cut are generally kept shallow. The approach to HFM involves using much larger peripheral speeds, higher radial cutting depths of cut and smaller cutter diameters.
The use of high peripheral speeds when cutting with HFM provides more efficient chip control and reduces the thermal load on the cutter. The cutting edge on an HFM tool applies a great deal of force to its cutting action due to the high engagement angle and resulting high tangential force. This intense pressure aids in the removal of the chip material, leaving a superior surface finish.
The smaller cutting diameter of the HFM tool produces a larger chip load compared to a larger-diameter tool. This allows for a faster cutting action and increases the feeding speed into the material. The larger chip load also means that the tool produces fewer revolutions. This is beneficial as too many tool revolutions causes the cutting edge to experience unnecessary wear and tear, thus reducing its life.
The high tool engagement angle also serves to reduce cutting forces and improve chip flow. This can be especially beneficial when cutting harder materials and those with a large amount of embedded chips, as these conditions can create more resistance to the cutting action and require more power to remove the chips. The high engagement angle also helps to reduce tool deflection, meaning that the tool maintains a more consistent distance from the part, resulting in a more accurate cut.
The high depth-of-cut and smaller tool diameter results in high material removal capacity. This is advantageous when dealing with larger parts, as fewer passes are required to get the job done resulting in a faster machining cycle time.
The greater engagement angle, smaller cutter diameter, and large chip material also helps to reduce overall tool vibration and prolong tool life. With higher engagement angles, chip evacuation is improved, resulting in less force on the cutting edge and less vibration from the cutting action.
This combination of cutting benefits makes HFM an ideal machining process for many applications and operation types. It is more efficient, cost-effective and accurate than conventional milling processes, as well as being highly reliable, especially when it comes to producing a superior surface finish.
