How to choose a diamond blade: segment, material and diameter

To choose a diamond blade you need to know three things: the material you are cutting, the machine you use, and whether you work dry or with water. For reinforced concrete and bricks a segmented blade is fine; for porcelain stoneware, ceramic and marble, a continuous rim blade; for general use, a turbo blade. The diameter depends on the machine: in the collection it ranges from 115 mm for the small angle grinder to 350 mm for cut-off saws and floor saws, with bores of 22.2, 22.23 and 25.4 mm and also 30 mm.

The types

• Segmented blade: the rim has segments separated by gaps, which help clear the material. It is the blade for reinforced concrete and bricks, like the laser-welded segmented blade U GOLD SGM Bossong.
• Continuous rim blade: the edge is one piece with no breaks, and gives a very clean cut on hard, brittle materials such as porcelain stoneware, ceramic and marble. Example: the blade S SILVER CC Bossong.
• Turbo blade: the edge has notches that cool the blade and clear the dust, for a fast and fairly clean cut on several materials. Example: the Turbo Quattro Sea Technology.
• Welded segment blade: in laser-welded blades, like the Laser Scan Quattro Sea Technology, the weld fixes the segments to the blade body.
• Wall chaser blade: used to open channels for pipes and cables in walls. The wall chaser works with two parallel blades, one for each side of the channel. Example: the Otto Sea 3D, designed for wall cutting.
• Blade for cut-off saws and floor saws: these machines need large diameters, because the cutting depth depends on the diameter. The collection includes 300 and 350 mm blades, such as the Disco diamantato UL (300 and 350 mm, bore of 25.4 or 30 mm) and the Disco diamantato alto rendimento CF2 Ø 350 mm Barikell. Always check the stated application on the data sheet.
• Diamond cup wheel: it does not cut, it grinds and roughs concrete and stone, like the single-row diamond cup wheel DT3795-QZ DeWalt.

Choosing by job

How to read the data sheet of a turbo blade: the Sea Technology example

The data sheets of the Sea Technology turbo blades do not just say "for concrete": they give a rating for groups of materials (from best to worst: SUPER, OTTIMO, BUONO, MEDIO, SUFFICIENTE, INADATTO). It is the most precise way to choose, because it shows that no blade is good at everything. From the data sheets of the three models in the collection:

• Turbo Tre Sea Technology: OTTIMO on cured concrete, bricks and roof tiles; BUONO on granite, natural stone, porphyry and reinforced concrete; MEDIO on marble, refractory materials, sandstone, slabs, gravel aggregate, double-fired and single-fired tiles; SUFFICIENTE on porcelain stoneware and klinker.
• Turbo Sei Sea Technology: SUPER on concrete, granite, natural stone and porphyry; OTTIMO on cured concrete, bricks, roof tiles, sandstone, slabs and gravel aggregate; BUONO on marble, refractory materials, double-fired tiles, porcelain stoneware and klinker.
• Turbo Quattro Sea Technology: SUPER on granite, porphyry and natural stone; OTTIMO on reinforced concrete, cured concrete, bricks and roof tiles; BUONO on refractory materials, sandstone, slabs, gravel aggregate, porcelain stoneware and klinker; MEDIO on marble and single-fired tiles; SUFFICIENTE on double-fired tiles.

One thing is the same for all three: fresh concrete and asphalt are rated INADATTO. If you have to cut asphalt, a general-purpose turbo is not the answer: you need a blade made for asphalt.

Sintered and welded segments: two different things

When a data sheet speaks of "sintered" or "welded" blades, look at two separate aspects. The first is how the segment is made: a sintered segment starts from a mix of diamond powder and metal binder, pressed and fired into a block. The second is how the segment is fixed to the steel body of the blade: it can be sintered directly, brazed or laser-welded.

What matters in practice: check on the data sheet whether the blade is meant for dry cutting, wet cutting or both, and do not rely on the name of the process. A blade designed for water and used dry overheats and loses segments.

The features to look at

• Diameter: 115 and 125 mm for small grinders, 180 and 230 mm for large ones, 300-350 mm for cut-off saws, bench saws and floor saws. Never exceed the maximum diameter allowed by the guard.
• Bore: 22.2 or 22.23 mm for grinders, 25.4 mm and 30 mm for larger machines; some data sheets list 25.4/20/15/10 mm with a reducer. The bore must match the spindle. If you use a reducer, check that it suits the machine.
• Thickness: from 1.6 mm to 3.4 mm. A thin blade cuts better and cleaner on porcelain stoneware, a thick one lasts longer on concrete and holds up in deep cuts.
• Segment height: in the collection it ranges from 2.2 to 15 mm (the Disco diamantato XV has 7 mm, the UL 10 mm). A taller segment holds more diamond and lasts longer.
• Application: general use, asphalt, porcelain stoneware and klinker, marble and ceramic, reinforced concrete and bricks. It is the data that matters most: read it first.
• Maximum speed: it is printed on the blade, together with the rotation arrow. It must be equal to or higher than the no-load speed of the machine.
• Dry or wet: cooling extends the life of the blade and cuts down dust.

Common mistakes

• Choosing only by diameter without looking at the application: a ceramic blade on reinforced concrete wears out quickly.
• Cutting dry without pauses: when dry cutting, let the blade spin freely now and then to cool it.
• Forcing the blade when it stops cutting. It is dressed on abrasive material.
• Mounting the blade backwards against the rotation arrow.
• Fitting a large blade on a machine without the right speed or guard.
• Using a turbo on asphalt or fresh concrete: on the Sea Technology data sheets it is rated INADATTO.
• Using a diamond blade on metal: metal needs specific abrasive discs.

Dust and safety

Cutting concrete, bricks and stone produces respirable crystalline silica dust, which is recognised as a carcinogen when inhaled. For this reason it is best to work with water or with extraction and to protect your airways, eyes and hearing. Some diamond blades in the catalogue state compliance with EN 13236, the standard on the safety of superabrasive tools.

Frequently asked questions

Which diamond blade is needed for porcelain stoneware?

A thin continuous rim blade, preferably used with water. The collection has an application dedicated to porcelain stoneware, klinker and ceramic.

Segmented or turbo for concrete?

Segmented is the classic choice for reinforced concrete and bricks. Turbo is more versatile and cuts cleaner, but is not designed for the heaviest cuts.

The blade has stopped cutting, is it scrap?

Not necessarily: it may have glazed over. It is dressed by cutting an abrasive material, for example a brick.

Can I use the same blade dry and wet?

Only if it is marked for both. A wet-cutting blade used dry overheats.

Can I use the same blade on a grinder and on a cut-off saw?

Only if diameter, bore and maximum speed are compatible with both machines. Always check the data sheet.

You can find all the models in the diamond blades collection: ask the AMES technicians for a quote or advice, stating the material, the machine and the diameter.