In high-speed circular saw cutting, material hardness directly affects blade peripheral speed, feed rate, feed per tooth, tooth pitch selection, and cooling/lubrication methods.
Simply put:
When cutting softer metals, higher cutting speeds and larger feed per tooth can usually be used, but chip adhesion, built-up edge, and chip evacuation must be carefully controlled. When cutting harder metals, cutting speed and feed per tooth generally need to be reduced, while more stable feed control helps reduce tooth impact, wear, and tooth chipping.
Therefore, a high-speed circular saw machine cannot use one fixed set of parameters for all materials. Even when the workpiece diameter is exactly the same, the original cutting parameters may no longer be suitable when switching from low-carbon steel to alloy steel, stainless steel, or high-hardness materials.
The essence of high-speed circular sawing is that multiple teeth on the blade continuously enter the material and form chips.
Each tooth must withstand a certain cutting resistance when entering the workpiece. The harder the material, the higher the cutting force generally required for tooth penetration, with more noticeable mechanical loading and local temperature rise. If high peripheral speed and large feed are maintained, the following problems may occur:
However, this does not mean that “the softer the material, the easier it is to cut." Aluminum, copper, and some low-hardness steels have relatively low cutting resistance, but they can show stronger plasticity and adhesion. If chip evacuation space is insufficient or blade peripheral speed and lubrication are selected improperly, chips can adhere to the teeth and form a Built-Up Edge (BUE).
Therefore:
The core challenge with hard materials is usually tool load and wear, while the core challenge with soft materials is often chip evacuation, tool adhesion, and chip control. This is why high-speed circular saw machines need different cutting parameters for different materials.
The following comparison provides a simple overview of the adjustment direction:
| Cutting Factor | Softer Materials | Harder Materials |
|---|---|---|
| Blade Peripheral Speed | Usually higher | Usually reduced |
| Feed per Tooth | Can be increased appropriately | Usually reduced |
| Overall Feed Rate | Can be relatively fast | Relatively slower |
| Tooth Pitch Selection | Greater attention to chip space | Greater attention to tooth strength and stable cutting |
| Cutting Resistance | Lower | Higher |
| Main Risks | Tooth loading, BUE, difficult chip evacuation | Wear, tooth chipping, overheating |
| Cooling/Lubrication Focus | Reduce adhesion and assist chip evacuation | Reduce temperature and friction |
| Parameter Stability Requirement | High | Very high |
It should be noted that these are adjustment directions rather than a fixed parameter table. Actual cutting parameters must also consider material grade, hardness, workpiece diameter, solid bar or tube, blade diameter, tooth count, tooth material, machine rigidity, and the target cutting cycle.
Peripheral speed is one of the most important parameters in high-speed circular sawing.
Basic relationship:
Vc = π * D * N / 1000
Where:
As material hardness increases, blade peripheral speed generally needs to be reduced appropriately.
The reason is that high-hardness materials increase the cutting pressure in the contact area between the teeth and the workpiece. If the blade continues to run at excessive speed, tooth-tip temperature and wear rate can rise rapidly.
For example, when switching from ordinary low-carbon steel to higher-strength alloy steel, the original spindle speed cannot simply be maintained even if the workpiece dimensions remain unchanged.
Conversely, for softer materials such as aluminum alloys, a high peripheral speed can often improve productivity, but the tooth geometry and lubrication system must be capable of controlling chip adhesion.
Therefore, when selecting peripheral speed, do not ask only: “What spindle speed should be used for this diameter?" Instead, first ask: “What peripheral speed is suitable for this material at its current hardness?" Then calculate the required spindle speed according to blade diameter.
If blade speed determines how fast the teeth cut, feed rate determines how fast the blade enters the material.
The feed rate of a high-speed circular saw machine must match the spindle speed.
For softer, easy-to-cut materials, the feed rate can be increased appropriately to shorten cutting time per workpiece.
However, when cutting high-hardness materials, an excessive feed rate increases the instantaneous load carried by each tooth.
Typical signs include:
Therefore, when machining high-hardness materials, stable load control is more important than simply pursuing a higher cutting speed.
Modern fully automatic high-speed circular saw machines can usually control the feeding process more precisely through servo feed systems, allowing more appropriate speed changes during blade entry, stable cutting, and blade exit.
Knowing the overall feed rate alone is not enough. For high-speed circular sawing, another critical indicator is feed per tooth.
It can be simply understood as the amount of material removed by each effective cutting tooth during one engagement with the material.
An excessively small feed per tooth is not necessarily safer. If the teeth only continuously rub against the workpiece surface without forming stable chips, frictional heat, tooth-tip wear, and blade wear can increase.
However, if the feed per tooth is too large, the teeth may become overloaded and even chip.
Therefore, for high-hardness materials, the load per tooth generally needs to be reduced appropriately. For softer materials with good machinability, feed per tooth can be increased within the allowable range of the blade to achieve higher productivity.
This is why evaluating a high-speed circular saw machine should not focus only on “how many seconds per cut." Long-term production efficiency depends on achieving a balance among tooth load, cutting time, and blade life.
When material hardness changes, it is not only the machine parameters that need adjustment; the blade itself is equally important.
For soft materials that tend to produce long or large chips, sufficient chip space must be considered. If the tooth pitch is too fine, chips cannot leave the cutting area in time and may clog the gullets.
For harder materials, a balance must be found between cutting efficiency and tooth strength.
Especially during high-speed cutting, if too many teeth are engaged at the same time, the cutting amount per tooth decreases, but friction and cutting heat may increase. If too few teeth are engaged, the load per tooth may become excessive.
Therefore, tooth pitch should not be determined independently of material hardness + workpiece diameter + cross-sectional shape + blade diameter + target cutting efficiency.
When cutting parameters change, the cooling and lubrication strategy should also be adjusted accordingly.
For materials that tend to adhere to the blade, one of the main purposes of lubrication is to reduce bonding between chips and teeth. If lubrication is insufficient, built-up edge and tooth loading can cause cutting quality to deteriorate rapidly even before the tool is actually worn.
Key points include:
High-hardness materials tend to generate greater cutting forces and local heat. Therefore, special attention should be paid to blade temperature, tooth friction, continuous cutting load, and thermal wear at the cutting edge.
Good cooling and lubrication can help extend blade life, but they cannot compensate for incorrect cutting parameters. If peripheral speed and feed per tooth significantly exceed the allowable range of the blade, simply adding more cutting fluid will not truly solve the problem.
For example, a factory originally cuts ordinary carbon steel and now needs to process higher-hardness alloy steel. Even if the workpiece diameter remains unchanged, it is recommended to recheck:
Chip condition is one of the important indicators for judging whether parameters are appropriate. A stable cutting process should produce relatively regular chips while keeping machine load within a reasonable range. If powder-like chips, unusually long chips, blue chips, excessive burrs, or severe tooth loading appear, the cutting parameters should be checked again.
Many users search after purchasing a high-speed circular saw machine: “What spindle speed should be used for 45 steel?" “What feed rate should be used for 304 stainless steel?" “What peripheral speed should be used for alloy steel?"
These data can be used as references, but they cannot be copied directly.
The reason is that even two factories cutting the same material may have completely different actual conditions, such as:
Therefore, the optimum cutting parameters are actually a combination of parameters matched to the material, blade, and machine, rather than a single spindle-speed number.
A more reliable method is to start with the recommended parameters from the blade and machine manufacturers, then optimize gradually based on actual production results.
The adjustment logic can be:
Not necessarily.
“Soft material at high speed, hard material at low speed" is only a basic trend, not an absolute rule.
What really determines the parameters is the material’s overall cutting performance.
In addition to hardness, the following factors should also be considered:
For example, stainless steel may not have the highest hardness among all metals, but because of its toughness, work-hardening behavior, and thermal characteristics, its high-speed sawing parameters often still need to be handled more carefully.
Therefore, material hardness is an important basis for setting parameters, but it is not the only factor.
For high-speed circular saw machines, the biggest difference between soft and hard metals is not simply whether the spindle speed should be increased or decreased.
What really needs to be adjusted is the entire cutting system.
Softer materials can usually use more aggressive cutting parameters, but special attention must be paid to chip adhesion and poor chip evacuation. Harder materials generally require lower peripheral speed and lower load per tooth, together with higher stability from the machine, blade, clamping, and cooling systems.
If the cutting parameters are selected correctly, it is possible to achieve:
Therefore, when selecting or using a high-speed circular saw machine, do not focus only on maximum spindle speed or the fastest cutting time. The real value of high-speed circular sawing is achieved by matching spindle speed, blade peripheral speed, tooth pitch, feed rate, and feed-per-tooth load according to material hardness and cutting performance.
اتصل شخص: Mr. Henry
الهاتف :: +86-18101486180
Arabic
