When it comes to cutting granite, marble, travertine or any natural stone there are many things you should consider to make your cuts and your work easier. Initially let's look at the material, including the thickness and length of the cuts. Are the cuts straight or curved? Are we talking about tiles or slabs? Make sure you use a respirator mask and safety glasses whenever you are cutting natural stone.
Once you know the material you are going to be cutting we need to determine what the best type of tool for cutting it is. Will you be using a grinder, a Skilsaw, a rail saw or a bridge saw? Although nothing is "etched in stone" you want to use common sense here. If you only own a 4" grinder and you are cutting 3cm thick granite it won't cut it straight and it won't cut all the way through the stone. Let's break this down to power tool and saw blade first, then we will discuss techniques:
Tiles - as a rule 12" square tiles are 3/8" thick while larger tiles are thicker. These should be cut with a tile saw as that is the easiest way to get consistently straight cuts. While 12" square tiles may be straight cut on a tile saw as small as a 7" wet saw, if you are diagonally cutting them or if you are working on pieces up to 20" square you will need a 10" tile saw. If you are using bigger tiles than that you will need to go to a 10" tile saw with an oversized tray and longer carriage travel. Make sure that you can make your cuts in a single pass. Do not use a saw where you can only get partway through the length of your cut and have to turn the tile around and match the cut from the other end. This will not look right and you will wish you had used the proper tool instead of trying to Mickey-Mouse it!
If they are marble tiles, travertine tiles or limestone tiles you can use any good tile blade that is rated for that material or for harder materials like granite or porcelain. If you are using granite tiles you need to use a blade designed for cutting granite or porcelain as the blade that is made for marble tiles, travertine tiles or limestone tiles will glaze on harder materials. That means that once the diamonds exposed on the cutting edge of the blade are worn out the metal bond of the blade is too hard for the material you are working with and the metal is not getting sheared away so no new diamond edges are being exposed. In other words the blade is now dull and will not cut anything. Once you have the correct tile saw and blade for cutting your natural stone tiles the rest is simply a matter of set-up. Make sure the tray is at a 90 degree angle to the cutting head and if you are using a rip guide make sure it is the correct place. Fill the water pan on the saw, plug it in and have at it!
We have a full line of wet cutting continuous rim blades for tile If you have to make curved or intricate cuts on stone tiles and the tile saw won’t work most contractors use a small diameter blade on a grinder and dry cut it. You can use a dry cutting continuous rim blade for chip free cutting of any tile, even porcelain tile, or a dry cutting turbo rim blade made specifically for granite and natural stone.
For cutting slabs of granite and partial slabs you cannot use a tile saw except on the smallest pieces as they just won’t fit. Now we have to look at other options:
1) Using a grinder -
Electric angle grinders are used on slabs for dry cutting, grinding, shaping, routing and polishing. When cutting keep in mind that if you are cutting 3cm thickness or larger you can’t do it with a 4 ½” blade. If you are making straight cuts don’t use a grinder as it is very difficult to make a straight cut with it and you will be creating extra work for yourself. If you are making curved cuts or plunge cuts you can use a grinder. For round or oval sink cutouts concave blades will save you time and make cutting your inside curves easy.
2) Using a Skilsaw (circular saw) -
For straight cuts is a great place to start for someone new to cutting slabs. These saws are usually used dry but you can get water attachments for some of them. If you are using the correct blade you will have dust but you will have true, smooth cuts. When you are using a Skilsaw to make straight cuts use a straight edge clamped to the slab as a guide. Make sure at the cutting point the blade is entering the polished surface, not exiting it as this will minimize chipping. Make sure the blade you are using is specific to the material you are cutting.
For marble use electroplated blades or brazed blades as they will allow you to make fast, clean chip-free cuts on this brittle stone. They are fast and aggressive without excess chipping or stress on the stone which can lead to cracks. For travertine you can use the same blades or you can use one of the blades for granite. While the granite blades will give much longer life than either the electroplated or brazed blades they have the tendency to chip the material a little more. A nice compromise are the dry continuous rim blades which are fast, chip-free and longer life than the first two styles.
For granite you should use a tight comb turbo blade designed for granite. We recommend any of the Supreme grade listed on our site.
3) Using a rail saw for straight cuts on slab is the next progression for a contractor. These are more precise and allow more options than a Skilsaw. They are easier to set up and allow greater flexibility in depth of cut, angle of cut and other options depending on the rail saw.
4) Using a bridge saw for straight cutting stone slabs is the way a stone fabrication company does it. You get better performance and faster cuts. These saws are usually 20 horsepower and will use diamond blades from 12” up. Most fabrication shops like their blades to be the silent core blades which keep the decibel level down in the shop. We carry them From Diamant-D, Diamond Services, Disco-Sea and Slayer.