Diamond blade for granite, marble or metal: how to choose

These diamond blades are made for one specific material: granite, marble, refractories, metal. On a different material they wear out quickly or stop cutting, so the first question is always what you need to cut. Then choose the diameter: from 115 to 230 mm with the angle grinder, from 250 to 625 mm with larger machines, with bores of 22.2, 25.4 or 30 mm.

The types

• Granite blade: for the hardest stone, like the Granito Cinque Silent by Sea Technology. The term Silent indicates the quiet version, useful in the workshop where noise is a concern.
• Marble blade: for softer stone that can be polished, like the Marmo Quattro Silent.
• Refractory blade: for bricks and refractory materials, like the Refrattari Cinque.
• Electroplated blade: the diamond is bonded to the blade body without welded segments. This is the case with the Elettro Tre, for precision cuts where little thickness is needed: check the data sheet for the material.
• Diamond blade for metal: for iron and steel, like the Metallo Cinque by Sea Technology, the Milwaukee Steelhead for steel and stainless steel and the DeWalt Extreme in 300 mm and 355 mm.

How to choose by job

The features to look at

• Diameter: from 115 to 625 mm. Up to 230 mm they are angle grinder blades; beyond that you need larger machines, such as cut-off saws or floor saws.
• Bore: 22.2 mm for the small sizes, 25.4 mm for those from 250 to 500 mm, 30 mm for 600-625 mm. The bore must match.
• Thickness: from 1.3 to 4.2 mm depending on the diameter. Thinner cuts better but is less robust.
• Segment height: 3, 4 or 10 mm. A taller segment holds more diamond and lasts longer.
• Use: dry, wet or both. Follow the marking: with water the blade is cooled and dust is cut down.
• Cutting width: for example 2.8 mm. It indicates how much material is removed by the cut: the wider it is, the more power the machine needs.
• Pack: the blades are sold individually. For daily use it pays to keep a spare.

Common mistakes

• Using a stone blade on metal, or a metal blade on stone.
• Fitting a blade of 300 mm or more on a machine that does not have the right bore, guard and speed.
• Cutting dry with a blade that is meant to be used wet.
• Ignoring the direction of rotation and the maximum speed.
• Not wearing goggles, ear defenders and a mask, even if the blade is the quiet type.
• Choosing the blade by diameter alone, without looking at what material it is built for.

Frequently asked questions

What is the difference between a granite blade and a marble blade?

Granite is harder and needs a blade built to withstand it; marble is softer and cuts best with a blade designed not to chip it.

Can I cut steel with a diamond blade?

Only with diamond blades rated for metal, such as the Steelhead or the Extreme for metal. An ordinary stone blade does not cut steel.

What is the refractory blade for?

For cutting bricks and refractory materials, which are very abrasive and quickly wear out an ordinary stone blade.

What does a quiet blade mean?

It is a blade built to reduce noise during cutting. It is mainly useful in the workshop, but it does not replace ear defenders.

How do I choose the diameter?

Start from the machine: the maximum diameter and the bore are shown on the rating plate and on the guard. A larger blade cuts deeper, but only if the machine and the guard allow for it.

Dry or wet?

It depends on the model: the collection includes dry blades, wet blades and blades for both. The marking is on the data sheet and on the blade.

You can find all the models in the stone and special-purpose discs collection: ask for a quote or advice from the AMES technicians, stating the material and the machine.