Steel cutting disc
Professional guide to choosing and using the right disc
Cutting discs for steel are an essential tool in any metalworking workshop, production line, boilermaking company, or industry dedicated to the maintenance and manufacture of metal structures. Choosing the right disc not only determines the speed and quality of the cut, but also the operator’s safety and the profitability of the process. In this article we analyze in depth how these discs work, what types exist, and which options are most suitable depending on the type of work and the steel to be machined.
Professional guide to choosing and using the right disc
A cutting disc for steel is a reinforced abrasive specifically designed to cut ferrous metals through a friction-based cutting process. Unlike a blade or conventional cutting tool, the disc does not “cut” the material with an edge; instead, it disintegrates the metal surface by abrasion, thanks to the high peripheral speed generated by the grinder.
It is composed of:
- Abrasive grain, generally aluminum oxide (corundum), chosen for its hardness and thermal resistance.
- Phenolic binder, which keeps the grains bonded together even under high temperatures.
- Aglutinante fenólico, que mantiene los granos cohesionados incluso bajo temperaturas elevadas.
- Specific additives, such as coolants or friction modifiers, depending on the model.
A steel cutting disc must have an abrasive structure capable of withstanding intense mechanical stresses, high temperatures, and hard metal slag. General-purpose discs or those intended for other materials can burn, wear unevenly, or even fracture if used on structural steel, which is why it is essential to use discs specifically designed for this material.
Types of discs suitable for cutting steel
The market offers a wide variety of discs, but not all perform equally well on steel. This material requires a balanced combination of
Carbon steel cutting discs (Aluminum oxide A)
They are the most commonly used in industrial environments. Made with high-quality
Extra-thin discs for stainless steel
Although they are optimized for stainless steel, many extra-thin models offer excellent performance on carbon steels, especially in cuts where minimal burr, reduced heating, and more precise control are desired. Their reduced thickness (typically 1.0–1.2 mm) lowers friction and allows for fast cutting of sheets, thin tubes, and low- to medium-thickness profiles.
Heavy-duty reinforced discs
Designed for tough jobs such as beams, thick plates, or solid welds. They incorporate multiple layers of fiber mesh and a more aggressive grain, which improves stability and safety when working on large-section pieces.
Long-life discs
Designed for repetitive processes or mass production. They maintain their cutting capacity for longer thanks to an optimized binder formulation and an abrasive grain more resistant to wear. They are especially useful in environments where reducing the number of tool changes is important.
How to choose the right cutting disc for steel
Choosing the correct disc is not just a matter of diameter or thickness; it directly affects work speed, safety, energy consumption, and cut quality. These are the technical criteria a professional should consider before selecting a disc:
Disc thickness
Thickness determines the balance between speed, precision, and durability.
- 1.0–1.2 mm: fine, fast cuts with minimal burr. Ideal for tubes, sheets, and thin profiles.
- 1.6–2.5 mm: greater stability and durability on thicker steels. Suitable for medium-sized structures.
- 3 mm or more: heavy-duty use or prolonged cuts on very thick profiles. Increases robustness and reduces the risk of breakage.
The choice depends on the thickness of the workpiece and the level of control required for the task.
Type of steel to cut
Not all steels behave the same under abrasion:
- Standard carbon steels: work perfectly with general-purpose aluminum oxide (A) discs.
- Stainless steels: require specific discs free of iron and sulfur to prevent contamination and subsequent corrosion.
- Alloyed or hardened steels: it is recommended to choose more aggressive discs or ones with higher thermal resistance.
Correctly identifying the material prevents overheating, premature wear, and inaccurate cuts.
Disc diameter
It depends on the available tool and the required cutting depth:
- 115–125 mm: the most common size for handheld grinders. Suitable for maintenance, workshop, and light construction work.
- 180–230 mm: deep cuts in beams, columns, thick structures, or production lines.
Using the appropriate diameter maximizes safety and maintains the correct peripheral speed.
Machine compatibility
The professional must ensure that the disc:
- complies with EN12413
- matches the machine’s maximum allowed speed
- matches the machine’s maximum allowed speed, is mounted with the correct flange, and shows no deformations
These precautions are essential to minimize risks such as breakage due to excessive RPM.
Type of work
- Fast cutting on site ⟶ thin discs.
- Mass production ⟶ long-life discs
- Structural work ⟶ reinforced discs
- Precise cutting for subsequent welding ⟶ discs that produce minimal burr
Selecting the right disc not only improves performance but also the final quality of the project.
How steel cutting discs work: technical fundamentals
The operation of a steel cutting disc is based on controlled abrasion. Each abrasive grain acts as a “micro-cutter” that removes small particles of metal. When the disc spins at high speed (8,000–12,000 rpm depending on diameter), the kinetic energy transforms the contact between the disc and the surface into extremely intense friction, capable of continuously wearing down the steel.
Three fundamental principles are involved during cutting:
Abrasive grain hardness vs. steel hardness
The industrial corundum used in these discs has a hardness greater than that of structural or carbon steel. This allows the grains to penetrate the metal surface without fracturing immediately.
Self-sharpening of the abrasive
As the abrasive grains wear down, they partially break away, exposing new sharp grains. This phenomenon, known as self-sharpening, maintains a constant cutting ability throughout the disc’s lifespan.
Thermal management
Cutting generates intense heat in the working area.
Steel cutting discs are formulated with resins and additives that:
- minimize heat transfer
- reduce the risk of burning the workpiece
- reduce the possibility of structural deformation
This does not occur in discs designed for other materials, which tend to degrade or vitrify under the temperatures generated by cutting steel.
Common mistakes when cutting steel (and how to avoid them)
Even the most experienced professionals can encounter problems during cutting if certain best practices are not followed. Steel cutting discs require technique, control, and material knowledge. Here are the most common mistakes and how to avoid them to ensure a safe, fast cut with minimal disc wear.
Using an incorrect disc for the type of steel
One of the most common mistakes is choosing a disc that is not suitable for carbon steel, mild steel, or stainless steel.
A non-specific disc can cause overheating, loss of cutting speed, grain vitrification, and even contamination in the case of stainless steel.
Solution: always use discs labeled for steel or stainless steel according to the application.
Working at the wrong angle
The cut must be made with the disc perfectly aligned with the workpiece. Cutting at a lateral angle causes:
- uneven wear
- risk of disc breakage
- deviations in the cut line
- increased vibration.
Solution: always keep the disc perpendicular to the material and avoid lateral pressure.
Excessive pressure
Applying too much pressure does not speed up the cut; on the contrary, it generates excessive heat that burns the abrasive, weakens the disc, and damages the grinder.
Solution: let the abrasive do the work on its own, applying light and consistent pressure.
Inadequate speed or improperly selected grinder
A disc designed for 80 m/s should always be used on compatible machines.
If a grinder with insufficient power is used, the cut will be slower and the abrasive grain will wear out sooner.
Solution: choose the appropriate machine and adhere to the maximum RPM indicated on the disc.
Not cleaning the surface before cutting
Rust, paint, or dust can interfere with the start of the cut, causing vibrations or sudden bites.
Solution: clean the surface with a wire brush before starting.
Cutting discs from Abrasteel recommended for steel
These are the Abrasteel cutting discs suitable for cutting steel:
Designed for clean and stable cuts on steel and ferrous alloys.
Excellent balance between speed, durability, and control.
Available in various diameters (115–230 mm).
Ideal for boiler making, metal structures, locksmithing, and industrial workshops.
They are not cutting discs, but they do complement the process for edge finishing, smoothing burrs, and preparing weld seams before welding.
Perfect for removing cut marks, preparing areas for painting, and performing controlled grinding on structural and stainless steels.
Your supplier of cutting discs for steel
Cutting steel is a critical operation in boiler making, metal structures, industrial locksmithing, and mechanical manufacturing. Choosing the right disc, applying precise technique, and avoiding common mistakes makes the difference between a professional job and a mediocre one.
At Abrasteel we have been supplying high-performance cutting discs for years to companies that need quality, speed, and safety in their daily operations. If you are looking for a reliable supplier with stable stock and expert guidance, our team is ready to help you select the right disc for each application.
Request information or a no-obligation quote
Fill out our form or contact our sales department directly to receive personalized technical assistance.
FAQs
What is a cutting disc for steel?
A cutting disc for steel is an abrasive tool specifically designed to make clean and controlled cuts on ferrous metals such as carbon steel, mild steel, or structural profiles. It is made from a mixture of abrasive grains (typically aluminum oxide), synthetic resins, and fibers that provide stability and resistance at high speeds.
Its formulation and hardness are optimized to penetrate the metal without deforming, without burning the material, and while maintaining fast cutting performance. Cutting discs for steel must comply with the EN12413 standard, which regulates their safety and performance.
How does a cutting disc for steel differ from a disc for other materials?
The main difference lies in the composition of the abrasive and the type of binder.
Cutting discs for steel are made with grains designed to withstand intense friction without losing cutting efficiency. In contrast, discs for stone or stainless steel use different blends depending on the hardness and the temperature generated by each material.
Additionally, a steel cutting disc maintains its structural stability even during long cuts, while other discs can vitrify, lose abrasive capacity, or wear unevenly if used on the wrong material.
Can I use a stainless-steel disc to cut carbon steel?
Yes, it is possible, but not ideal.
A stainless-steel disc typically has formulations free of contaminants such as iron or sulfur and is designed to reduce heat. Although it can cut carbon steel, its performance may be lower and its wear greater if used frequently.
To achieve maximum speed, durability, and efficiency, it is best to use a disc specifically designed for the type of steel you are working with.
What disc thickness should I use to cut steel?
It depends on the type of cut and the application:
1.0 mm – 1.2 mm: fine, fast, and precise cuts on sheets or thin profiles.
1.6 mm – 2.0 mm: versatile use on metal structures and general workshop tasks.
2.5 mm – 3.0 mm: robust cuts on thicker sections or very hard materials.
A disc that is too thin may deform on thick pieces, while one that is too thick will unnecessarily increase cutting time.
Why does the disc wear out quickly when cutting steel?
The usual causes of premature wear are:
Excessive pressure on the tool.
Using a machine with insufficient power.
Cutting with the disc tilted or applying lateral force.
Using a disc that is not specific for steel.
Working at speeds below or above the recommended levels.
Dirty, painted, or rusty surfaces that make it difficult to start the cut.
By following technical recommendations and choosing the right disc, the service life increases significantly.
What speed should the grinder have to cut steel?
Cutting discs for steel are designed to operate at around 80 m/s, which translates into varying RPM depending on the diameter:
115 mm → approx. 13,300 rpm
125 mm → approx. 12,200 rpm
230 mm → approx. 6,600 rpm
Respecting the speed is crucial to avoid breakage, vibrations, or loss of abrasive capacity.
You should always check the maximum speed indicated on the disc label.
How can I ensure straight and clean cuts in steel?
To achieve a professional finish:
Keep the disc completely perpendicular to the material.
Avoid lateral pressure.
Make controlled and steady movements.
Clean the surface before starting.
Use quality discs that are in good condition.
Ensure the workpiece is properly secured with clamps or vices.
Let the abrasive do the work without forcing it.
Thermal control is key: less heat = cleaner cutting.
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