Guide written by:
Michael, Professional and passionate welder, Sheffield
A thermal cutter can cut concrete, asphalt and stone and is used in civil engineering, public works and building. With a cutting depth ranging from 145 mm to 400 mm discs, the cutter is also available in pneumatic and electrical models and can be dry-cut or water-resistant.
- Cutting depth
What is a cutter?
When it comes to portable machines, the cutter is undoubtedly the most imposing and requires at some muscles in the arms! Due to its specificity, it is mainly used by professionals. Nevertheless, the manufacturers have thought of all the potential users and offer wide ranges among which the sensible handyman will find the cutter that suits him.
Also called a thermal grinder, a cutter is a robust and quite heavy tool, weighing around 11 kg. The cutter is a bit like the grinder's big sister. It is often used outdoors to cut concrete, stone, asphalt, tiles and slabs. It also has applications in cutting pipelines, cast iron pipes in a trench, or extrication by firefighters. The thermal cutter has become increasingly easy to maintain and has become one of the most reliable tools on the market.
Cutter: thermal, pneumatic or electric?
Machine preferred for its autonomy, it is often equipped with a 2-stroke motor. Its use is mainly for outdoor work and is by far the most powerful cutter on most construction sites. It is available with:
- 2-stroke engine with easy maintenance air filter - essential to extend its life and to prevent engine damage due to dust. It is equipped with a 90 cm 3 cylinder and a power of 4 CV, or 3.5 kW;
- Pull-start starter system;
- Optimized cooling for intensive use;
- Central or lateral arm for sections close to walls and curves;
- High speed of 4000 to 4500 rpm;
- Cutting disc 350 to 400 mm for a depth of cut of up to 145 mm;
- Water supplyconnectionkit for when for cutting concrete;
- Weight of approximately 10 kg (minimum and no load) and noise level in up to 110 dB when in action.
This type of machine also exists in industrial versions on heavy-duty frames. Purchasing these models represents a significant investment.
Some manufacturers have had the good idea to propose a specially conceived trolley for the cutter, to give the operator an optimized comfort of use. The best part of this setup, the trolley's wheels are adjustable and displaceable to shave edges and walls. This trolley allows precise adjustment of the depth of cut. It is however also linked to the need for a large gravity water reservoir or pressur adaptable cointainer.
If you go even further with your research, you might even happen upon a model offering an extended arm (the cut and break example). These machines allow the cutting of walls up to 400 mm in a few steps. They are of course designed for that specific use.
Pneumatic cutting machine
Very heavily relying on compressedair, it must be connected to a compressor that can feed its voracious appetite. Air flow and pressure are the two values to check for to assure proper operation. The pneumatic cutter, which is less present on construction sites, is designed for all interior and exterior work and is characterized by:
- The need to have a powerful source of compressed air nearby - with a minimum air flow rate of 2.8 to 3.5 m 3 per minute and pressure of 7 bar;
- Its ergonomics. Because of its weight and its narrow and long form, a pneumatic cutter is recommended for sensitive areas such as poorly ventilated areas and trenches. This is due to the absence of smoke evacuation, which would be required with it's termal counterpart;
- Its performance compared to the thermal model;
- Its discs, adaptable from 300 to 400 mm in diameter;
- The presence of water supply connection required for the cutting of the concrete.
Electric or battery powered electric cutter
The perfect choice for any job limited to masonry or tile work, especially relating to the construction of a house. The electric model is more practical, but has a limitedcutting capacity of 70 mm. The electric cutter allows the realization of indoor works, as long as they don't generate too much dust and offers:
- 350 mm disk, which results in a cutting depth of 125 mm;
- Electronic overload protection for the engine;
- Rated power from 1800 to 2700 W;
- Water supply connections with flow control;
- Weighs less than the other models of cutters.
Other types of cutting machines
Hydraulic cutting machine
An expensive machine since it must be attached to a hydraulic unit close-by. This cutter is designed for use in specific areas, such as flooded areas, and can even be used by a diver operator - quite often also used by firefighters and rescuers.
Marble glass tile cutter
As its name suggests, this cutting machine allows the cutting of tiles and glass via its diamond disc and offers:
- A 45° tilting blade with either dry cutting or lubrication;
- Performance lower than the thermal cutters with a maximum power of 1200 - 1300 W;
- A grinding wheel with a diameter of 125 mm;
- 40 mm deep cuts;
- A weight of 2.6 to 3 kg.
Special machine optimized for rapid shearing of concrete irons. It is a complementary tool to the thermal or pneumatic cutter.
The use of cutters is not without risks. PPE, Individual Protective Equipment, is available and compulsory for operators:
- Reinforced gloves;
- Anti-cuts jackets;
- Pants and leggings;
Basically, the equipment generally used by professional logers is what you need!
Discs for to this type of machine are classified according to their specific use. Be sure to carefully follow the manufacturer’s instructions before starting a job. Never assume that "This concrete disc will do the job for cast iron or steel ... no time to change disc ...", it’s your security that is at stake!
Helmets and visors
For passionate hobbyist, DIY lovers and heavy duty professionals looking for the right equipment, follow the links below for sanding-related accessories, advice from our editors and more helpful guides:
- How to choose your grinder?
- How to choose your bench grinder?
- How to choose your grinder accessories?
- How to choose your lubricant, grease and oil?
- How to choose your compressor?
- How to choose your interior floor tiles?
- How to choose your outdoor floor tiles?
- How to choose your wall tiles?
- How to drill tiles?
- How to choose your portable tools' battery?
- How to choose your portable tools' battery charger?
And to work safely
Guide written by:
Michael, Professional and passionate welder, Sheffield, 68 guides
I was trained as a pipe worker and a pipe-welder and after having traveled for 35 years working around the UK, I became the head a metal shop and then a designer and in the end the head engineer. I have designed and built a workshop where I make metal sculptures: I managed to find a piece of paradise where I can to let my imagination run wild. Auctions and garage sales are no secret to me. I find unusual objects and old tools there that I collect or transform into works of art. I also like decoration, painting on canvas, and gardening. I am developing new technologies concerning tools. To share my passion and humbly advise you in your choice of materials is a real pleasure.