Chop Saws are the second most used cutting tools in Fabrication. The first is of course the Angle Grinder. Before we start with the topic, let us first know the metal cutting options available for a DIYer. Not everyone needs a Chop Saw. There are multiple other ways to cut metal. This Chop Saw Buying Guide has all the answers for your questions. But before that let us know your needs.
Is steel the only metal you are going to cut? Do you cut wood? What about Aluminium?
You can also cut wood and aluminium in chop saw just by using the appropriate TCT blade. Using Abrasive blade on wood will overload the motor and produce a lot of smoke (not recommended).
If you want a chop saw for wood, you better invest for a mitre saw (compound saw). The reason is just to make the job easier.
Note: Never cut Aluminium with an Abrasive Wheel. This will burn the Aluminium and clog up the wheel. It is even dangerous to do so. Molten aluminium may fly off towards the operator.
How straight should be the cut?
If you need 100% straight cuts, then there are two options. You can buy either a Chop Saw or a Band Saw. Band Saws are quite expensive and arrive in two variants. One for portable use and other for stationary. Using a portable version of Band Saw won’t give you straight cuts. But cuts straight better than an Angle Grinder. In an Angle Grinder you can’t just cut large metals in one pass whereas Portable Band Saw can do that.
The other method is using a manual Hack Saw. Trust me, you can get straight cuts. But marking the job before the cut is very important. You can use portable reciprocating saws too. They are generally called Saber Saws. They also have multiple uses.
If you only have an Angle Grinder and need an accurate cut, then you need to mark the cut on all its faces before proceeding. An example, if you want to cut a Square Tubing, using some measuring tool, mark on all the faces of the tube. Then start cutting gently just on one face. Stop the cut after the marked line erases off. Don’t dig in deeper. Repeat for the other three sides. You will get a 100% straight cut. Now, don’t ask me how to get a 100% straight cut on a Pipe. In that case you should buy at least an Angle Grinder Stand attachment for your Grinder.
Size of the Material?
If you need a chop saw just to cut about 1 inch of material, then Angle Grinder Stand attachment might be sufficient. For larger size go with Chop Saw.
Using Angle Grinder Stand attachment would be an inexpensive chop saw conversion. But they have a limitation. You must decide the maximum cut diameter. If you use a 4 inch Angle Grinder, then you can cut material up to 1 inch diameter material in one pass. You can’t cut more without re-clamping the job. The reason here is that the housing of the grinder becomes an obstacle to cut more. If you own a 5 inch grinder, you can cut up to 1.5 inches in one pass. Please read our article on Angle Grinder Attachments and Accessories.
How much loss of material is acceptable?
Let us know what material loss is. A Chop Saw disc has a thickness of 3mm. This means you will lose that 3mm of material during the cut. So you should consider that 3mm loss of material before you mark your project.
Even a WoodCutting and Aluminium Cutting Disc also has 3mm thickness.
4 and 5 inch Angle Grinder Blades have 1.2mm thickness.
7 inch and 9 inch Angle Grinder Discs have 3 mm thickness.
Band Saw Blades have about 1mm thickness.
How fast you want the cut?
If you want the fastest cut, go with a Chop Saw. Abrasive Discs are the fastest to cut. The only problem during multiple cuts is, it takes more time to change a Chop Saw disc than an Angle Grinder disc.
Nowadays 14 inch metal cutting Diamond Discs are also available. The advantage here is, you need not change discs at all. One disc will last much longer as 30-60 Abrasive discs. The disc won’t get shorter. The disadvantage is their speed. They cut slow. If you compare a Band Saw with Diamond Disc, both have similar cutting speed.
Now let’s talk about Chop Saws itself. I have not discussed any chop saws smaller than 14 inches. I don’t think they are Value For Money as they are priced more or less the same.
Here are the specifications to look for when buying a Chop Saw.
Induction Motor vs Brushed Motor
14” Chop Saws have two types of power inputs. One uses an Induction motor and the other Brushed Motor. Industries use Induction motors as they are efficient and reliable. Induction motors can run longer without overheating. And moreover the motor is silent. For DIYers, cheaper Chop Saws will just work fine.
Brushed motors generally have power ratings of about 1800 to 2400 watts. You can choose any power rating you want. Higher the power, faster it will cut.
Chop saws with induction motors are connected to the arbor through a V belt. This increases the working capacity as space consumed by the brushed motor is reduced. So for the same disc size, you can cut about 25% more material. The cutting disc gets more utilization.
Major advantage of induction motorized Chop Saws is that it weighs very heavy. This is due to the weight of the motor. If you are looking for a portable saw, this is not for you.
Generally, Induction motored saws have fixed type Safety Guards. Brushed motor saws have auto engaging guards.
For Induction motors, choosing a 3 Phase power supply over Single Phase is recommended. A 3 Phase motor is quite small in size while compared to a single phase motor of the same power rating. 3 Phase motors have more torque than a single phase motor.
Induction motors are very silent compared to universal brushed motors when running at no load speed. While cutting, noise is generated. That’s obvious.
Generally Chop Saws arrive in two types of Handle Variants. One is Horizontal and the other is Straight (Vertical). Choosing between them is completely personal preference. My personal preference is horizontal handle as it feels comfortable and gives more control over the trigger switch. And applying force on the work is very easy.
Bosch GCO220 has Vertical Handle
Dewalt D28870 has Horizontal Handle
14 inch (355mm) Chop Saws can cut up to 4 inch ( and slightly more) sized solid round bar in one pass. If your work size is 5 inches, you should go with a 16 inch Chop Saw.
14 inch Chop Saw with an induction motor can cut up to 5 inches easily. But, here is a small catch. When the Chop Saw is set at 45°, you cannot utilize the blade for more than 2.5 inches on each side. Like said above, 4 inch cut is possible with a new blade only.
All Chop Saws have the same Work Clamping mechanism.
All have the same type of Angle Adjustment.
All Chop Saws have guard for the blade. Let it be as it is.
More the weight, better it can tackle vibrations.
A 2400 watt Chop Saw draws about 10 amps of current at 230 volts. 20 amps in the US at 115 volts. Generally 230 volt power sockets are rated at 5 amps in India. Drawing 10A from 5A socket is not recommended. Socket may be able to handle that load but the wirings may burn off. So, choose wisely according to your Socket Ratings.
Never use it inside someone’s house. In case wiring gets burnt, then repairing them is not easy because in modern houses wirings are hidden inside the walls. So a Chop Saw is for workshop use only. If you are in need of a Chop Saw but don’t have a workshop, then look for low powered chop saws like the 7 and 9 inch model.
Chop Saw Safety
You should never use a Chop Saw without its Safety Guard. You cannot judge or estimate when the disc will shatter. Discs can also shatter due to manufacturing defects.
Don’t use very old abrasive discs. All abrasive discs have shelf life. Bent abrasive wheels will create vibrations and may shatter. Check its condition before usage.
And the rest is basic safety. Be Safe, Work Safe.