Have you ever wondered how stone, gems, and glass is cut, smoothed, and polished to create a sparkling luster? Most slabs of granite or marble are cut using high-pressure water jets to create accurate cuts without shattering the stone. While this can result in a very accurate cut, there is often roughness in the stone or rock material that needs to be smoothed over using a variety of specialized grinding machines.
Not unlike belt sanders, grinding machines help smooth edges to give stone and metal a safe, even, and professional finish. Surface roughness is defined using minute variations of a material; because this means more or less dealing in microinches, the roughness can go undetected by the naked eye. Specialized edge grinding machines are used to precisely smooth edges and corners for a variety of commercial and residential applications depending on the material and the intended function.
Jewelers, lens makers, and other high-precision fields often need to be even more precise than microinches to produce an appropriate finish; this is where lapping comes in. Lapping is a machining process by which two surfaces are rubbed together with an abrasive in-between; this can be done by hand or single side lapping machines. In addition to single side lapping machines there are double side lapping machines available in a variety of sizes to process parts as large as 20 inches in diameter or as small as .002 inches in diameter. Gems, jewelry, glasses lens: these are finished using precision lapping machines. The surface flatness is measured in Helium Light Bands which measures units of height as small as 0.000011 inches — precision lapping machines please even the most obsessive-compulsive of craftsmen. So next time you look at a gem, put on a ring, or take off your glasses, consider the detail and accuracy that went into its creation — it just goes to show how important even the smallest details are.