Most granite cutting takes place at the quarry, but some will probably have to be done at the installation site. It’s essential that the proper equipment is used.
To shape the dense material, a standard household skill saw needs to be upgraded with a diamond cutting blade. These are available at major home improvement centers for about $45. Pros also have a trick they use to avoid chipping the edge of the granite, which is caused by the blade’s vibration. Collars that act as big washers on both sides of the saw’s blade reduce the vibration, allowing a cleaner cut.
When granite is cut dry, a considerable amount of dust is generated. Some installers will use a handheld diamond-bladed radial saw with a vacuum attachment to help minimize the mess. A contour diamond blade is needed to cut out curves like sink openings.
The edge design of the countertop can be shaped in a number of ways: flat, beveled, curved or rounded. But it can be a challenge to cut the edges so they match perfectly or meet precisely in a corner — unless you have access to an automated edge-shaping machine that both cuts and polishes the edge.
Assuming you don’t want to buy an expensive piece of equipment, one option is to have a local company cut the edges for you. Typically they’ll charge a fee per square foot that includes cutting, edging, profiling and polishing the countertops. Extra fees may apply to sink cutouts (getting these accurately sized for under counter-sink mounts is tricky).