In a lathe, it represents the number of revolutions the spindle makes per minute, while in a milling machine, it indicates the number of revolutions the cutting tool makes per minute.

Feed anddepth of cut

Many CNC lathes, milling machines, and multitasking machines have built-in cutting conditions tables as internal data and are equipped with systems and software that automatically set appropriate values when materials and types of machining are selected. Additionally, some manufacturers offer apps that can be used on smartphones or tablets for this purpose.

Cutting speeddefinition

Cutting conditions vary depending on the material of the workpiece and the cutting tool, as well as the desired shape to be cut, and must be adjusted each time these factors change. If the cutting conditions are not appropriate, various disadvantages can arise, such as poor machining accuracy, longer processing times, and tools chipping or wearing out prematurely.

Considering the machine condition and its effect on accuracy, the actual value is often set lower than the recommended value.

Depth of cutformula

Due to the wide variety of cutting materials, tool materials, and tool shapes, there is no definitive answer regarding cutting conditions. This often leads to confusion and uncertainty, especially for beginners. First, use the recommended values or those set automatically by the system. Verify the accuracy of the machined workpieces, ensure that the machining time is not excessive, evaluate whether the load on the cutting tools is excessive, and make adjustments as necessary. As you gain experience, you will be able to determine cutting conditions smoothly.

When a workpiece pushes back against the cutting tool during cutting, it’s called cutting resistance. The ratio of cutting resistance to the cutting cross-sectional area is called specific cutting resistance. It varies depending on the material of the workpiece, and approximate values are as follows:

By consistently performing the best target cutting process from all perspectives, you can achieve high quality machining and reduce man-hours.

Definition of depth of cutin machining

In addition to the above decision-making of cutting conditions, further adjustments are made to determine the optimal priority and balance, such as prioritizing machining accuracy or slightly increasing the machining speed.

Depth of cutCalculator

Maintaining a balance among the various machining factors while optimizing all of them can be quite challenging. For example, prioritizing machining speed can lead to increased load and vibration on the workpiece and cutting tools, which can in turn affect precision and the lifespan of the tools. Deciding what to prioritize and finding the right balance is a case-by-case matter, and there is no single correct value.

When cutting a new workpiece, if you have machined a similar material and shape, you can make an adjustment based on previous experience.

However, due to the wide range of factors such as material, shape, and required accuracy, it can be challenging to completely rely on automated settings for all machining tasks.

Depth of cutformula for turning

If the theoretical surface roughness exceeds the specified tolerance for surface finish, adjustments such as altering the feed rate or switching to cutting tools with larger cutting edge nose radius may be necessary.

When metal is cut using a lathe or milling machine, chips are generated in various forms such as spirals, ribbons and shavings. It’s said that you can tell a lot by looking at the color, shape, length, etc., of the chips.

Cutting speed represents the speed of cut per minute.In the case of a lathe, rotation is also involved, and it is referred to as the peripheral speed.

To perform machining, a machine tool needs to have specified numerical values for cutting speed, rotation speed, feed rate, and depth of cut, which are referred to as cutting conditions (or machining conditions).

Depth of cut definitionin lathe machine

The load is calculated based on the current value flowing through the motor. The load value can be used to adjust machining conditions while machining.

This is a phenomenon where fine chips become part of the cutting edge, causing adverse effects on machining accuracy. It is more likely to occur with materials that have high affinity with iron.

Depth of cutformula for milling

In actual machining, further adjustments are required to account for the influence of material properties. Rough estimates suggest that for steel, the influence is 1.5 to 3 times, while for cast iron, it ranges from 3 to 5 times. Additionally, the cutting edge nose radius varies depending on the selected cutting tool.

This is the result of combining the above cutting conditions with the cutting resistance to represent the actual power required by the motor.

Since cutting tool has a large influence, each cutting tool manufacturer lists recommended values in their catalogs. Various materials are available, but those with high hardness and heat resistance can perform high-speed cutting, while those with high toughness are durable and can be used for long machining time.

If the depth of cut is excessive, it can cause vibration due to deflection (chatter). Conversely, if the depth of cut is insufficient, it can lead to surface sliding phenomena (slip phenomenon, rubbing phenomenon).