Choosing The Right Diamond Blade

If you select and use your diamond blades correctly, they will provide a good working life, good cutting speed and value for money.
Similarly, if the wrong blade is selected or it is misused, then you will lose money by damaging the blade or wearing it out very quickly.

There are many factors to consider when choosing which UDT Diamond Blade to purchase. These include:

The Price

For frequent use and larger jobs, it is better to choose a more expensive Premium Series diamond blade as they will deliver a longer life and a lower cost per linear metre of cutting.  However for occasional use and smaller tasks, it is quite often preferable to choose from the lower priced Trade Series diamond Blade.

Quality and Size of Saw or Grinder

  • It is all based around the horsepower and RPM of the tool being used to complete the task. Diamond blades are rated to match the RPM of the saws and grinders. High speed handheld saws and high speed cut-off saws need blades that are rated at higher RPM. Electric wall chasers need different blades from petrol powered ones.
  • Check both aspects of your machinery prior to choosing the product to suit. This ensures not only value for money, but also more importantly SAFETY.

The Material Being Cut

It is most important to correctly identify the material you are going to cut prior to choosing a Diamond Blade. This has a major effect on the cutting speed and life of the Diamond Blade.

Most materials fall into four categories: Hard, Medium to Hard, Medium to Soft and Soft. The harder the material being cut, the softer the bond holding the diamonds needs to be. This allows the bond to wear and exposes the diamonds to cut the product and releases the diamond before it glazes over and makes the blade useless. Conversely, when cutting soft materials, it is important to have a strong bond that holds the diamond segments and increases the life of the blade.

Many people choose the hardest blade and believe it will cut everything. This is a false belief as hard bonded blades will not cut hard product! As a general rule, determine the material which will be cut most often, or the material for which blade performance is most important.

If a  blade is to be used to cut more than one material (for example, asphalt and concrete pavers) determine which material will be cut the most often and buy a blade suitable for that material.

Try to Avoid:

Combi blades - combination blades often claim to be able to cut any construction material including steel. In reality, they usually have quite hard bonds. When cutting hard materials, their hard bond makes cutting hard, which overloads the saw (on brick saws causes the electric motors to trip out, and can cause hand saws to bounce and kick). Generally, a combi blade will continually glaze up when cutting less abrasive materials such as clay pavers or bricks.

General Purpose blades -  tends to be at the cheaper end of the price range, and maybe okay for a handyman or light user.  Normally a general purpose blade would have segments that are of medium hardness, which means that it is suitable for cutting a range of building materials. But they would not be very good for hard or abrasive materials like asphalt or limestone, causing them to wear very quickly.

Sintered blades -  Sintering is a cheaper manufacturing process and is generally considered to be not as secure as laser welded blades for holding segments on the blade.  It tends to be used on cheaper blades, so always look for laser welded blades.

Diamond blade cost is usually a minor factor in the overall cost of the job - labour and overhead costs are usually much greater. Therefore it is important to select a diamond blade that can provide the best performance and productivity, not just the lowest blade cost.

What Blade Do You Need For Cutting?

We always recommend discussing your requirements with us, as there are many variables to diamond blade selection. But here is an indication of product specific blades we stock and sell.

Asphalt is highly abrasive and can wear blades extremely quickly. If cutting a lot of asphalt always use a United Diamond Tools black blade.

Green concrete is concrete that has set but not fully hardened or cured. Full hardening may take up to months to occur. Green concrete is also highly abrasive, so use a United Diamond Tools black blade.

Sandstone and limestone is not as abrasive as asphalt, but still use an United Diamond Tools black blade. If it is reconstituted limestone, we recommend a white blade.

Concrete, reinforced concrete, concrete kerbs and pipes as well as concrete pavers require a United Diamond Tools white blade.

If you are regularly cutting a combination of asphalt, limestone and concrete we would recommend using a UDT black asphalt blade. While it is always preferable to use the recommended diamond blade for each unique material, the black blade will cut perfectly on asphalt and limestone and will be good on concrete (although it may glaze up after a while. Fix this by cutting some asphalt or limestone to "open  up" the blade again).

Wall chasing - we have a special range of blades in various thicknesses and diameters specifically designed for chasing and grooving walls.

Exposed aggregate is best cut with our black chasing blades - these blades have good undercut protection if you go through to the under base. They are also ideal for use on green concrete. If you have exposed aggregate pavers, these are different composition and need a white blade.

Clay pavers cut with a brick saw requires a United Diamond Tools silenced blue blade. We also have unsilenced blue blades for hand saws, although a concrete blade will often be sufficient.

Ceramic and porcelain paving is extremely hard and very brittle. Using a hand-held cut-off saw can be tricky, so a tile saw is much better.  Segmented blades cause the pavers to chip or shatter. Even specific stone blades will likely cause chipping and flaking of the very hard surface. Use a Continuous Rim Ceramic or Porcelain Blade for best results.

Porcelain is manufactured using very special porcelain clay that is fired at very high temperatures to create an exceptionally hard tile with almost zero water absorption. 'Ceramics' is general term that includes terracotta, stoneware and earthenware as well as porcelain. Porcelain is a ceramic, but not all ceramics are porcelain.

Alumina ceramic and silicon carbide is used in wear plate manufacture. As a ceramic, it needs a similar blade to porcelain. However, alumina ceramic is often mounted with rubber, so cutting becomes very complicated. Contact United Diamond Tools for advice on our range of blades that will cut without chipping in this complex application.

Granite is very hard, so requires a blade with a softer bond like the UDT pink series. These blades will wear out extremely quickly if used to cut any of the more abrasive materials above.

Refractory brick and marble are both very hard applications, and these require specialist blades for cutting without cracking or chipping. Contact UDT for a quote on the right blade.

Fibreglass and glass need our electroplated tile saw blades.

Rescue blades - Vacuum brazed blades will usually cut a wide variety of material including concrete, masonry, steel, various irons, plastic, tile, wood and glass. They are also used to cut rail line. The Fire Brigade will use them on "rescue" saws, so they are often are called rescue blades. They perform well in dry applications, but the blade will last longer if water is used with them.

Core Sample blades are widely used across the Western Australian Goldfields and in the mining industry for cutting core samples. We carry many specific core cutting blades for cutting very hard materials.

Material Abrasiveness Bond UDT Blade
Limestone, sandstone Extremely Hard Black
Asphalt
Green Concrete
Concrete pavers/pipes/kerbs Very Medium White 
Reconstituted limestone
Concrete Slabs, precast
Reinforced Concrete
Clay Bricks & Pavers Abrasive Medium/soft Blue (or white on cut quicks)
Granite & hard clay bricks Low Soft Pink 
Alumina/Ceramic Low Soft Specific range of  blades
Refractory applications Low Soft Specific range of  blades
Ceramic Low Soft Continuous rim ceramic
Porcelain Low Soft Continuous rim porcelain
Marble Low Soft Specific blade

We always recommend discussing your requirements with us, as there are many variables to diamond blade selection. But here is an indication of product specific blades we stock and sell.

Blade Problems:

Glazing : As a diamond blade is used, the bond wears, exposing more diamond that continue cutting. If the bond does not wear back, then eventually there is no diamond exposed, and so the blade will slow down and stop cutting. The cutting edge of the blade will feel smooth. This is known as glazing or polishing
Possible causes are:

  • The bond is too hard for the material it is cutting - select the correct blade.
  • The machine is not powerful enough for the specification (usually experienced more with professional blades and saws)
  • The blade has been mounted with the rotation arrow the wrong way.

Rectify by re dressing the blade by cutting an abrasive material like limestone to remove some bond and expose diamonds so cutting can continue.

Short blade life - Generally caused by using a bond which is too soft for the material being cut. Select the correct blade for the application.
It usually occurs when cutting more abrasive materials such as asphalt, green concrete or sandstone (which requires a UDT black  blade). Wet cutting will also extend the life of a blade compared to dry cutting.

Disclaimer: the information on this website is provided in good faith and believed to be reliable and accurate at this time. However, the information is provided on the basis that the reader will be solely responsible for assessing the information and its veracity and usefulness. UDT shall in no way be liable, in negligence or howsoever, for any loss sustained or incurred by anyone relying on the information, even if such information is or turns out to be wrong, incomplete, out-of-date or misleading.

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