We recently wrote about choosing the right electric cutter for porcelain tiles and today we will focus on a more general topic, the range of diamond cutting wheels, especially from RUBI, their characteristics and their use for different tile materials.
For quality and efficient cutting of tiling materials or tiles, 3 basic conditions must be met: a suitable cutting tool (e.g. RUBI, Kaufmann or Battipav hand cutter or electric cutter), the correct cutting wheel for hand cutters or diamond wheel for electric cutters, and finally the skill and experience of the tile cutter.
There are different types of diamond blades for cutting cladding materials. However, knowing how to cut each material is a key skill for a tiler to achieve a quality result. Understanding how facing discs are made, manufactured and function will help you better understand what type of disc you need, or which type is best for cutting each material.
Diamond cutting discs
Let’s start with some basic information about diamond blades. Diamond cutting wheels consist of a circular body (core), usually made of steel. The diamonds are connected to the core in the form of a continuous edge or in segments. This cutting material, also called a diamond strip or blade, can be bonded to the core of the blade in a variety of ways, but the most commonly used method is laser welding. The blade has a very high abrasiveness (grindability) which is used in the actual cutting process.
The type of bonding of diamond grains can be done in three different ways: sintering, electroplating or vacuum brazing. In the case of specific ceramic cutting wheels, we will mostly talk about sintering. In the sintering process, the diamond particles (grains) are mixed with a metal binder and fused together using high pressure and temperature. This creates a structure with different layers of diamonds that are revealed as the blade gradually wears (abrades). This bonding of metal and diamond is sometimes called bonding.
The relationship between the diamond grain size, the concentration of these grains and the hardness of the bond (binder) varies according to the requirements of each wheel.
- If we are cutting hard materials, we use the small grain type with a high concentration of diamonds and a soft binder.
- If we are cutting abrasive materials, we use a large grit, low diamond concentration and a hard binder.
- If we are cutting several types of materials, we usually use a large grit, low diamond concentration and a soft binder.
Ideally, both the binder and the diamonds are cut at the same time. If we have a soft binder, the metal will wear faster and the diamonds will always be on the surface and ready for efficient cutting. In this case, the life of the blade will be negatively affected, especially when cutting abrasive materials.
Conversely, if we have too hard a binder, the diamonds will wear out without gradually replenishing themselves. This is due to the bonding agent not being cut at the same time as the diamonds, and the tool loses its cutting efficiency. This is when we say the blade is “dull”. Cleaning/grinding blocks that are superabrasive can be used to solve this problem. The cleaning block wears away the blade’s bonding agent and diamond particles from the underlying layers appear on the surface. These blocks will also remove any dirt left on the blade after a few cuts.
Sintered diamond discs
In our shop we have a wide range of sintered (in other words sintered) diamond discs available not only from RUBI, but also from SOLGA, SIMA, DISTAR, CARAT or BATTIPAV.
Using the RUBI diamond blade list as an example, we will outline the differences between the different types of blades and their blades. Below is a list that shows the differences between the different types, also with examples of the models that you can find in the Tiler-Market store:
All-round blade – Provides the best finish. Used for cutting tiles less than 25 mm thick.
Dry – CSV, CPR / Wet – CEV, CPA, CPC
TURBO blade – Great combination of cutting properties. High performance and cutting speed with high quality finishes.
Dry – TCR, TSV, TLG / Wet – TPI, TON
VIPER blade – Evolution of the TURBO knife with even higher quality of cut and also speed. It is the ideal blade for materials with high hardness.
Dry – TVA, TVR, TGS / Wet – TVH
Segmented blade – These are the fastest blades. They provide maximum cutting speed and better blade cooling. They are suitable for cutting materials over 25 mm thick.
Dry – STT / Wet – SHR
TURBO segment blade – They are suitable for cutting all kinds of materials at high speed.
J-groove blade – Cutting-edge blade technology delivers high cutting speeds in the toughest materials. These blades are specifically designed for direct cutting of porcelain tile. Eliminates stresses created during cutting.
Dry – CPJ / Wet – CPX, SPT
When assessing blades, it is always important to remember that the higher the cutting speed, the lower the quality and vice versa. The blades with the most balanced speed/quality ratio are the TURBO and VIPER types.
How to choose a diamond wheel?
Now that we have described how diamond wheels work, how they are made and their types and basic characteristics, we need to consider the following three aspects when choosing the right wheel:
1. What type of cut do we make?
Depending on the type of cut we are going to make, we should think about what type of machine we are going to use. An electric cutter or an angle grinder? And then, what type of cooling do we use?
Depending on your cutting tool, whether it is an electric cutter or an angle grinder, it is always necessary to choose the appropriate blade diameter, its centre hole and also the maximum speed for which it has been designed.
Surely each of you knows that diamond blades cut material based on the principle of friction. Since they are superabrasive, this friction creates high temperatures during cutting that need to be reduced (cooled). This leads to two types of cutting: dry cutting and wet cutting.
In dry cutting, cooling during cutting is done only by the air movement generated by the blade itself as it rotates. “Dry” cutting wheels can be water cooled for greater durability and better surface finish. “Wet” cutting wheels must always be water cooled.
In our range you will find many different diamond blades for dry or wet tile cutting. Therefore, you need to know which machine you will be using and also the type of cooling during cutting before making a decision.
2. Types of materials we need to cut
The second thing to consider is the type of materials you will be cutting.
When you want to cut ceramics or ceramic materials, both fall into the silica group. These materials, composed mainly of silica, have a medium-high hardness, although some may also contain particles with very high abrasiveness.
The most common siliceous materials are the ones we are most interested in: ceramics or ceramic materials such as ceramic tile, glazed stoneware or porcelain stoneware. This group also includes glass and granite.
Because of the hardness of these materials, we will need a combination of small grains with a high concentration of diamonds and a soft binder that wears simultaneously with the diamonds to prevent dulling of the blade and to ensure that the blade continuously delivers the required cutting performance.
3. Cutting speed vs. execution quality
Thirdly, we need to consider in what proportion we prioritise cutting speed and cut surface finish quality.
This will depend on the types of cuts being made, as it is not the same to make a straight or diagonal cut, where we may prefer cutting speed, as it is to make a mitre cut (angled cut), where we need high precision and the resulting quality of the cut.
Not all blades are suitable for all types of cuts. For miter or miter cuts, we need blades with enough reinforcement and core thickness to withstand a 45° cut without vibration or breakage. The minimum core thickness for mitre cuts can vary depending on the diameter of the blade. Worth mentioning are the angled cutting discs from DISTAR’s EDGE series.
To summarise, once we have considered whether we will be wet or dry cutting depending on the machine used, the hardness of the material to be cut, such as ceramics, and whether we need to prioritise cutting speed or surface finish quality, we are ready to choose the most suitable diamond blade.
Classification of diamond discs by colour
To make it easier for you to choose the right blade, several manufacturers use a colour classification of blades. Each colour tells us what use or application the disc is originally designed for. This is how companies such as RUBI and SOLGA do it.
RUBI
- Red – mainly for porcelain
- Purple – designed for common building materials
- Light green – for common ceramic material
- Dark green – universal discs for various building materials
- Blue – for hard materials
- Orange – for abrasive materials
- Grey – for marble
- Yellow – for other materials
SOLGA
Wet cutting
- Green – for ceramic materials
- Red – for hard ceramics and porcelain
- Blue – universal discs for different building materials
- Blue with black stripe – for abrasive materials
- Dark red – for interlocking paving
Dry cutting
- Red – for ceramics
- Dark red – for hard ceramics and gres
- Black – for abrasive materials
- Orange – universal discs
- Blue – ideal for bricks and pressed stoneware, can also be used for natural stoneware and concrete
- Gold – for different building materials
We hope that after reading this article, it will be easier for you to choose the right and best blade for cutting cladding materials. If you still couldn’t choose from our selection, you can consult us either by phone or email.
The article is based on RUBI’s documents.