When setting out to choose a carbide slitting saw, you should never settle for less. You need to pay attention to the appropriateness, and overall safety of the saw for jobs over merely getting the job done. With the right saw, you can get the job done efficiently with little or no stress at zero risks.
This article to equip you with the requisite knowledge and understanding in this niche. Furthermore, specific technical details and information pertinent to your selection process are succinctly discussed in paragraphs to follow.
Fig 1: Picture showing carbide slitting saw.
Table of Contents
1.Types of carbide slitting saw
Bearing in mind that carbide slitting saws are prominent for their high precision and accuracy. Its performance still very much depends on the blade’s tooth geometry and stick-out diameter:
• Tooth Geometry
Below are the tooth geometry variations of carbide slitting saw:
a.Standard Tooth Slitting Saw: This usually comes with more teeth per inch and lesser thicker than its coarse counterpart. Owing to these properties, it can give you a very fine and better finish of your workpiece. Due to more teeth around the circumference, it has a higher feed rate of which also contributes to the excellent finish it gives. It is generally considered ideal for finish passes. However, it is more expensive due to the higher number of teeth.
b.Coarse Tooth Slitting Saw: This has exactly opposite properties to the Standard tooth slitting saw provided all other things are equal. It has a higher thickness than standard tooth lesser tooth per inch, fewer teeth, more opening for better chip evacuation, allows for deeper cuts. They are the best fit where a smooth finish is not critical. The sum of all these properties makes it far cheaper than the standard tooth slitting saw.
• Blade diameter
On the other hand, the blade diameter typically ranges from 3 to 4 inches. You, therefore, have to pick the smallest diameter needed to give you the depth of cut you desire based on the thickness of your workpiece. Also, ensure that at least two teeth of the slitting saw come in contact with the workpiece through the tool’s revolution Note that the larger the diameter, the higher the chances of wobbling and runout.
Fig. 2: Carbide slitting saw showing several teeth geometry.
2.Material to be cut
The nature and type of material you intend cutting informs your slitting saw selection process, it helps you decide how much lubrication you need to avoid chips from getting welded to the workpiece during cutting.
Knowing how tough, brittle, or hard your metal is, help you determine the right saw thickness for you. In your best interest, select the best saw thickness for your application such that it would not break or fail in service at all.
Cutting of Zinc, magnesium, aluminum, brass, bronze, plastics, and none-metals requires a specific type of carbide slitting saw while machined steel, cast iron are also cut with another configuration of carbide slitting saw. Ensure you pay attention to this to get a great saw capable of cutting to your desired depth.
3.Choose an appropriate arbor and saw hole diameter
The arbor carries the saw and is usually attached to the tool holder or spindle taper of your CNC machine. In a bid to minimize deflection and maximize rigidity of the carbide slitting saw, the largest possible diameter of the arbor should be selected. The arbor plays a significant role in the accuracy of your cut. If you choose the wrong arbor, then you are bound to experience great danger as well as risk your workpiece getting ruined. For example, a 1 -inch arbor has half the strength of 1.25-inch arbor.
You should take the length of your arbor into due consideration as well to ensure proper reach.
In the same vein, the saw hole must also complement the arbor diameter. However, as mating parts similar to a hole and shaft assembly, some level of tolerance is needed. The final assemblage of the saw on the arbor ensures the overall rigidity of the assembly and prevents deflection. Do not forget that the larger the arbor size, the larger the saw hole.
Fig 3: Saw hole on carbide slitting saw.
4.Extent of cut
No matter how deep you want to cut on your workpiece, the carbide slitting saw can help you achieve this. It just requires some technique(s), which are pivotal to your selection process. Unlike its counterpart- HSS slitting saw, the carbide slitting saw is a specially developed saw with the ability to cut seamlessly through metal mainly.
If you are looking to make deep cuts, there are two generally accepted approaches- The first approach is to make shallow cuts multiple times and progress in that manner. The other approach is to cut to your required depth in a single pass without making shallow cuts.
For the first approach, chips are quickly eliminated and are discontinuous. On the other hand, for the cutting in one pass approach, chips accumulation is likely to cause problems. From experience, the first approach is the most preferred by professionals. It is because it gives the best accuracy and reduces overheating by providing room for intermittent cooling.
Fig. 4: Cutting of very thick metal rod.
5.Be Sure of Your Feeds and Speeds
By a rule of thumb, the larger your carbide slitting saw, the slower it should run. It is to reduce the amount of heat to be generated and minimize deflection and instability. It is, therefore, imperative that you calculate the appropriate feeds and speeds for your use. Even though there are quite a lot of calculators out there to this for you, the fundamental parameters needed are:
i.Your saw’s diameter and the number of teeth.
ii.Your saw’s thickness.
iii.Your intended depth of cut.
You can apply this formula to get speed: RPM = (SFM x 12) ÷ (Tool Diameter xℼ).
Where SFM- Surface feet per minute cutting speed
The parameters can be used on feeds and speeds calculator to get the exact value needed for programming the CNC machine before commencing cutting. By using these calculated values, you are sure to eliminate all issues of overheating since you are not overworking the sitting saw blade.
Another catch to using correct cutting speed is the safety and durability of your saw. Excessive speed can lead to instantaneous dulling of your carbide slitting saw as a result of this costing you money and time. Do not forget that carbide slitting saw cost far more than the HSS slitting saw. You also must take note of the direction of rotation of your blade to place your workpiece to ensure the correct feed.
6.Heating and Coolant
Here again, we need to emphasize the sensitivity of the carbide slitting saw blade to heat. Due to small teeth and tiny gullet between teeth, heat substantially generated during cutting. In making your choice, you have to ensure flood coolant availability is guaranteed and will not destroy or attack your blade to help dissipate heat and lubricate the stick-out section of the saw.
For instance, materials like aluminum tend to get welded to their chip without proper lubrication put in place. Then the flood coolant is critical as it can penetrate the narrow slot to get the job done.
Fig 5: Flood coolant in action during cutting.
7. Types OF Milling
Milling refers to any act that involves removing chips from a material. In the case of a carbide, slitting saw, there are two forms of milling, namely:
• conventional milling: If you have rigidity in your setup is limited. The maximum cutting force is in the upwards direction towards the end of the cutting cycle. The chips generated is initially very thin and steadily increases through the cutting cycle. Avoid injury and fracture of your blade by the backlash is minimal.
• Climb Milling: When you have a rigid arbor and blade, then a climbing mill is the best fit for the job. The chip generated is often thick and thins out during the cutting cycle, while the maximum cutting force is downward at the end of the cutting cycle.
To conclude this article, you should take away this basic principle of carbide slitting saw selection, which is- “To always use the smallest thickness and diameter of saw blade alongside the largest possible arbor.” You should also take it upon yourself to look-out properly for all these enumerated factors to select the best slitting saw suitable for your need without posing any risk to yourself. For more information and help, do well to contact us at NCCuttingtools. We remain dedicated to providing you with a state-of-the-art cutting tool-related solution all at pocket-friendly rates.