Iran Stone

How to Cut Granite

Granite is an igneous rock which solidified from a fluid state with a crystalline textured. It is usually comprised of quartz and microcline. Special tools are needed for cutting into, drilling through or shaping granite because of its hard surface. To cut granite in any way, you will require a masonry diamond blade. Masonry diamond blades range from 4 inches to 24 inches. Diamond blades are used for wet and dry cuttings.

During the time that a diamond blade is used, you can use a table, tile or handheld saw for cutting granite. Use these saws wet or dry depending on the job. Use a table or tile saw to cut through small, flat pieces of granite such as granite tiles. Use a handheld saw for larger pieces such as sculptures and counter slabs.
You can rent both the saw and the blade from hardware stores that have a tool rental service.

Bit compared to Blade

•    For slicing through granite you will use a diamond blade. For drilling through granite you will need a diamond bit. You can use a diamond bit to drive holes through granite countertops for installation applications for faucets.
Wet cutting compared to Dry Cutting
•    Using a wet saw with a wet diamond blade decreases the risk of chipping or breaking the granite. Wet cutting also reduces heat and makes it easy to cut through granite. You typically use wet cutting blades for walk behind saws such as a tile saw. These saws have a tub under the blade that water is stored so as to be continuously spread onto the blade. When using this saw, water will trickle out onto the ground and spray a mist around the saw, so it should be used outside. Use a wet blade for deep cuts that go through granite.
The dry cutting decreases the mess of wet saws but produces more dust. If you are cutting granite indoors, a dry cut is the best option because a wet saw creates large amounts of water. Dry cutting blades have segmental joints which resist heat and do not require water for cooling. Use a dry cutting blade when using a handheld saw with low horsepower to contour or shape granite.

Kinds of Blades

•    Standard Masonry Blades used for cutting straight though granite slabs and tiles.
Laser Welded Segmented Blades used for general purpose cutting.
Contour Blades used for twisted cutting applications.
Rod Blades used for cutting grooves into granite. Also used for sink applications.
Diamond Drill Bits used for milling through granite.
Profile wheels used for shaping and polishing the edges of granite.
Grinding Cup Wheels -- For smooth shaping and finishing granite.
Most diamond blades and diamond bits are manufactured for wet or dry applications or both.
Saw Manufacturers Institute (SMI) has built a common blade application code for using on diamond blades of 12" diameter or larger. Use of the code by blade manufacturers and distributors is completely voluntary.

Warning about blades

•    Based on the Association of Equipment Manufacturers, you may use many dry blades as wet blades. However, never use a wet blade as a dry blade. It is a dangerous performance.
Safety
•    You can download and read a free version of the Diamond Blades Safety Manual from the Association of Equipment Manufacturers. This brochure covers general safety information like blade wear and condition analysis, mounting, and machine safety.
Since granite is very hard and plentiful, it is widely used as a building material, both because it is beautiful, but it is highly resistant to wear. Tools with cutting blades covered with industrial diamonds are used to cut, carve, shape, and machine granite and other hard stone. Tooling with tungsten carbide edges can be used for certain applications, but professional stores use diamond blades. These are not gemming quality stones, but diamond that is nonstandard as jewelry because of color or other defects. Much more diamond is used for industrial aims than to make jewelry, which partly explains its expense, though diamond cutting implements cost a lot more than other kinds.

In the old days granite was cut with abrasive saws that had to have grit constantly fed into them. It was tedious, dangerous, and extremely harmful to breathe. Modern high speed tools, combined with diamond covered cutting edges, make the entire process comparatively safe and rapid.
Granite is very hard. In fact, the only harder substance on earth is diamond. As a result, diamond is the most common material used for cutting granite. It is also the only one capable of cutting it without damage to the granite or the cutting implement. Granite stands up well to virtually any normal kitchen task and, with proper care, will last for many years and retain its general quality.

To clarify the stages of cutting granite, we show an example:

Suppose you have a countertop made out of Verde Peacock granite, and you are remodeling the kitchen and need to remove a section that is near your cooking range. You don't want to remove the stove and lift the slab because the thin sections around the range are glued down. The slab is 25" wide and backs into the kitchen wall. There is a short (1.5") stone back splash and tile. Now you should cut the granite stone:
A mason recommends using a 4.5" grinder with a diamond blade for dry or wet cutting.

Some questions raise here that you should ask the mason:

1- Do you recommend this method?
The answer is: I have used a grinder for years with metal work but haven't done much stone cutting on countertops. I'm thinking it takes a slow steady series of passes so as not to pinch the blade and someone should take the vacuum to keep the dust down. I would use dry cutting to avoid damaging the cabinets below.
2- Would you recommend a jig to keep the blade utterly?
3- Can you recommend a kind of polishing pad for dry polishing of the cutting edge?
Also, the countertop you will be removing is heavy and long and fastened with silicone caulk. Any tips on how to cut the seals that you can see and how to get the top off without any destruction? Boards to support the free edge and a couple of jacks cranked little at a time? Nowadays, quarrymen cut and carve granite using saws with steel chisels and diamond-edged blades.
But Egyptian quarrymen and stonemasons didn't have these modern tools on those ancient times. Then, how, did they quarry and cut such clean lines in their obelisks and other monumental statuary?
To find out how ancient Egyptians quarried huge pieces of granite for their obelisks, scientists and Archeologists traveled to an ancient quarry in Aswan, located 500 miles south of Cairo. This is where the ancient Egyptians found many of the huge granite stones they used for their monuments and statues that we can see them now.
Archeologists believe Egyptian quarrymen used to pound out the trench around the edges of the obelisk. They then lifted the pulverized granite dust out of the trenches with baskets. Evidence also exists that workers pounded underneath the obelisk until the monument rested on a thin spine.
They say that huge levers were probably used to snap the obelisk from its spine, freeing it so it could be carved more finely and transported.
They know that the ancient Egyptians had the skills to forge bronze and copper tools. The Stonemason takes up a copper chisel, which works well when carving sandstone and limestone rock, to see if it might carve granite.
The stonemason simple experiment makes this much clear: The Egyptians needed better tools than soft bronze and copper chisels to carve granite.
As a young man, Denys Stocks was obsessed with the Egyptians. For the past 20 years, this ancient-tools specialist has been recreating tools the Egyptians might have used. He believes Egyptians were able to cut and carve granite by adding a dash of one of Egypt's most common materials, sand.
He says "We're going to put sand inside the groove and we're going to put the saw on top of the sand", "Then we're going to let the sand do the cutting."
It does. The weight of the copper saw rubs the sand crystals, which are as hard as granite, against the stone. A groove soon appears in the granite. It's clear that this technique works well and could have been used by the ancient Egyptians.
Then he will wash away dust that acts as a buffer to the sand, slowing the progress.
Though,adding water makes it harder to pull the copper saw back and forth. While he is convinced water improves the rate of work, his measurements show that the rate of cutting is the same whether water is used or not.
The Egyptians also drilled cylindrical holes into their stones besides cutting clean surfaces on their granite. A hole eight inches in diameter was found drilled in a granite block at one of their temples.
The stonemason says "Even with modern tools like stone chisels and diamond wheels, we would have a tough time doing such fine work in granite".
He was brought along to test his theories about how the cores were drilled. Inspired by a bow drill seen in an ancient Egyptian wall painting, he designs a home-made bow drill. He wraps rope around a copper pipe that the Egyptians could have forged. They then pull back and forth on the bow, which is weighted from above. The pipe twirls in place, rubbing the sand, which etches a circle into the stone. With the assistance of the sand, the turning copper pipe succeeds in cutting a hole into the granite slab.
With the assistance of a bow drill and sand, the pipe has cut a circular hole into the stone. But how can the drillers get the central core out?
He wedges two chisels into the circular groove. The core breaks off at its base. The stonemason reaches in and plucks it out, leaving a hole behind not unlike the ones once cut by the Egyptians.
And finally: Summarizing the steps on how granite is cut:
1. Templating;
2. Using variable speed angle grinder;
3. Straight cutting with grinder and turbo blade;
4. Curved cutting with contour blade;
5. Smoothing curve cuts with drum wheel;
6. Polishing undermount sink with dry polishing pads;
7. Drill a faucet hole with Sure-Guide and dry core bit