Since the advent of saws, the circular saw has stood out as the first choice when it comes to cutting metals. Users have attributed this to many reasons, such as its portability, ease of handling, and high efficiency. Advancement in technology saw the introduction of many other modifications to the design and use of the circular saws. It is for these reasons that we consider it necessary to enlighten you on the use of metal cutting circular saw. We believe by doing this; then you can get the best out of your circular saw from start to finish.
Fig 1: A new circular saw showing metal blade.
Table of Contents
1.Choose the right saw blade.
Metals come with various properties, but among those prominent for daily needs are mild steel, stainless steel, iron, and aluminum. Therefore, in cutting these types of metals, not just any kind of saw blade can be used. Furthermore, these blades will also vary based on the thickness of metal, strength, tooth design, the direction of cut, etc.
Blades vary for ferrous and non-ferrous metal cutting. Different grades of metal saw blades to cater to a wide range of metals are in the market. HSS metal saw and Carbide-tipped metal blade are the two major categories of metal saw blades as of today. Metals such as aluminum are known to be fragile in that wise cutting them requires a special metal saw blades.
Metal saw blades with fewer/ lower teeth cut thicker metals, while thinner metals require blades with more teeth. What this means is that the saw blades appropriate for cutting iron rods would slightly differ from that of the iron sheet. It will, in turn, completely different from that used to cut aluminum sheet or stainless steel. Depending on the thickness of the ferrous or non-ferrous metal as well. Use a metal blade of about 60-100 teeth for non-ferrous metals. Ferrous metals would require a 30-80 teeth metal blade.
For example, you should consider using ten teeth per inch saw blade for sheet metals less than 1/6-inch thickness. For materials up to 1/8-inch thickness, then a 12 tooth per inch saw blade is perfect. As the thickness of the metal increase, so should the tooth per inch of the metal saw blade reduce. Even though the carbide-tipped saw blades are more expensive, they make up for it with their exceptional durability. Carbide-tipped saw blade have up to 10 times stronger than regular steel saw blades. Asides this, they also give you a very smooth and accurate cut.
In simple terms, choosing the right blade is as good as getting the job done already! The right blades should be powerful enough to cut through seamlessly and not get stuck in the workpiece.
Fig.2: Carbide-tipped metal saw blade.
2.Lubricate the saw blade for protection
Knowing fully well that any metal cutting process generates a substantial amount of heat due to friction. What this mThis prompts the necessity for a lubricant to reduce heat at the interface of cutting. It is a common phenomenon for metal cutting circular saw blade experience overheating if not properly lubricated. Lubrication does a lot of good to ease your cutting task by ensuring the following:
a.Reducing the risk of injury due to blade grabbing workpiece.
b.Prolong the tips of the carbide-tipped saw blades by helping to dissipate heat.
c.Minimize possible friction between the saw blade and workpiece.
d.It also helps to wash debris off the surface of the workpiece.
You can lubricate using a special metal cutting lubricant, which does not, in any way, attack or harms the metal workpiece. Instead, it makes it luster and gives off a smooth and clean cut. Finally, with a saw blade wax stick, you can apply the lubricant along the line of cut intermittently.
Fig.3: Lubrication of metal blade while cutting.
3.Use appropriate blade depth.
The general rule of thumb is that you never allow your blade to go ¼-inch (6mm) beyond the workpiece thickness. It means that regardless of your workpiece thickness, the blade must be pre-set ¼-inch plus its thickness. The design of circular saws with the ability to adjust its blade depth has made it stand out among others.
Bear in mind that you must have initially set the recommended depth before putting on your circular saw. Failure to set the depth to standard can lead to binding, kickbacks, and safety issues arising. Generally, blades should barely stick beyond the workpiece thickness and cut more efficiently when a properly set this way.
4.Be Mindful of saw and blade’s speed.
The whole point of being mindful of speed is because you would want to use a blade within the limit of your circular saw. This act helps to ensure that both your circular saw and metal blade are kept healthy at all times. Usually, 5000 revolutions per minute (rpm) at no load is the average speed at which metal can cut using a circular saw.
Non-Ferrous metal such as aluminum, brass, and copper, the ideal speed is about 3000 to 6000 rpm. Ferrous metals such as pipes cast iron U-channels are cut with speed about 1800 to 3500 rpm.
Once you flout this rule, your blades get overheated, your power circular saw runs idle, or you get badly injured. Often, manufacturers indicate the safe and maximum rpm of blades on its packaging. Hence, for any combination of blade and saw, the blade’s rpm should remain greater, and the circular saw remains lower. With this, you are sure you cannot go above the limit and can keep working safely on your project.
Another perspective to choosing the right speed is that stability is sure when handling the circular saw at this speed. Never force the blade through the workpiece; neither should you run too fast through your workpiece. Remember, slow and steady wins the race.
Fig. 4: Close-up image of the metal blade running at high speed.
5.Safely Install the blade on the power saw.
Just like table saws, the metal blades rest upon an arbor. However, due to the nature of the circular saw, one must pay attention to details as mistakes could cost a fortune. Unlike the table saw, circular saws could cause more damage if handled carelessly. Ultimately, ensure all the nuts, bolts, and attachments all align in the right place. Your ability to correctly assemble the blade remains pivotal to the success of your job. You can check out your circular saw’s manual for more information.
6.Secure and Position the workpiece appropriately.
In using the circular saw, there is a need to position not only the workpiece but yourself as well properly. Positioning yourself is important as this puts you at absolute ease when working, and you can deliver a good cut. Asides from yourself, the placement of your workpiece is pertinent to the success of your cutting.
There is a dire need to properly secure the workpiece with clamps, vices, or fences as appropriate at all times. Do not ever make the mistake of not doing this before any cutting operation. Also, you would do yourself a lot of good by keeping to all procedures guiding pre-cutting operations and preparations.
By obeying this rule, you can keep both hands on top of the circular saw when cutting.
7.Observe all safety tips
At all times and situations, safety remains key. It is, therefore, integral to keep all safety tips in mind when working. Below are two major tips to ensure you work safely:
a.Watch out for metal chips
Never underestimate the havoc metal chips causes. They are not only sharp and can cut one’s skin, but they are also pretty hot when cutting is on-going. In recent time, circular saws have chips collector attached to them. Only purchase a circular saw that has this essential accessory. Warn bystanders around your work environment to tread carefully.
b.Wear all proper safety gears
For this reason, highlighted above, you need to cover your body properly with gloves and long-sleeves. Wear safety glasses or face shields as well as hearing protection.
In your best interest, you must always carry out routine maintenance on your circular saw to always keep it in shape. With this, you can avoid disappointment and always stay ready to work.
However, some people advise that wearing a glove could do more harm than good. These set of people believe gloves could get stuck on the teeth during operation and draw you in.
Fig. 5: Picture showing a man on safety gear while cutting metal.
It’s just not about having a circular saw for metal cutting; it is about using it effectively. We are confident that you have gained a lot. Endeavor always to use the specific circular saw and blade for the right task. In any case, where you find yourself still facing difficulties do well to watch this video. NCCuttintools remains positioned to provide you with guidance about appropriate cutting tools to suit your need at pocket-friendly prices.