Machine Cutting Methods and Applications

Milling is performed by rotating a cutting tool called a milling machine mounted on a spindle. Because the tool comes into contact with the secured workpiece intermittently for cutting, a wide variety of machining is possible, including cutting flat planes or curves into the workpiece surface, or boring or grooving the workpiece.

Different types of milling machines are available according to the orientation of the spindle: horizontal machines, vertical machines, and gantry machines, which feature a main body shaped like a gate. Using tools such as face mills, end mills, and slot cutters, these machines cut materials into the desired shape.

General-purpose milling involves the milling operation being performed by an operator. Moving the tool and workpiece in relation to each other, the operator determines and sets the cutting conditions, including the tool position and the feed, speed, and cut amounts. This manual method ensures a refined, high-quality finish.

CNC milling involves milling under cutting conditions controlled by a computer. Before CNC milling, numerical control with punch cards were used for milling program control (referred to as NC milling). Today, computer numerical control (CNC) has become the mainstream milling process. The automated operation reduces the labor involved in the process, and enables more complex shapes to be cut through programmed control using 3D CAD or CAM software.

A machining center is a multi-functional CNC machine that features multiple spindles with different tools mounted, including milling tools. Using a machining center makes it possible to serially combine linear and rotational motions for continuous cutting such as boring and curvature surfacing to create more complex shapes.

Computerized CNC gear cutting machines can cut teeth for gears of any shape, size, or purpose for use in daily life, from clocks to automobiles.

With general-purpose lathe machines, the operator manually performs feed operations and exchanges tools. The workpiece is held in place by a holder called a chuck, and is rapidly rotated for cutting. With a tabletop bench lathe, small parts can be machined on a workbench.

Controlling the machining conditions of lathe processing using a computer makes it possible even for beginners to create products at a certain level of quality. Some models also support automatic changeover of multiple tools for improved work efficiency.
Cam-operated automatic lathes were conventionally used to manufacture the same-shaped products from a long rod material―just like sliced hard candies. In recent years, however, cams have been replaced by programmed control in CNC automatic lathes.

Machine cutting performance depends on the relationship between the cutting tool and the material. Machine tools offer the necessary motion and rigidity for controlled material removal, while the cutting tools provide the sharp edge that executes the cut.

Common machine tools used in machining operations include lathes, milling machines, drills, and saws, and each type supports a different cutting motion. Each is selected based on the geometry of the part being produced. Broaching and boring machines may be used when a workpiece needs an internal feature or requires a hole.

Material properties also influence tool selection. Hard alloys and stainless steel are more costly for cutting tools and often require specialized inserts or coatings. Softer materials can be cut more quickly, but they run the risk of cutting too much or too deeply.

Sheet materials are often processed with shearing or thermal cutting equipment, and bars and tubes are commonly cut with saws or milling machines before any additional machining operations begin.

Achieving consistent results in machine cutting requires attention to both the machining strategy and process control. Cutting parameters such as spindle speed and depth of cut can influence how efficiently materials are worked with and how stable the cutting process remains.

Proper materials and tools need to be selected for the appropriate job. Toolpath planning plays a role in maintaining consistent force as it moves across the workpiece. Coolant and lubrication are often introduced to reduce heat buildup and help extend the life of the tool set.

Even when machining conditions are optimal, several factors can contribute to variations in metal cutting processes. Tool wear gradually changes the geometry of the cutting edge, which also causes changes in dimensions or can alter surface finish.

Manufacturers can address these challenges by incorporating measurement and inspection into the workflows. Dimension verification systems, like the IM-X1000 by KEYENCE, allow machinists to confirm that any machining operation remains within tolerance. If adjustments need to be made, operators are alerted early on to prevent scrap and rework.

Enhance machine cutting precision with advanced measurement and inspection solutions from KEYENCE.