Granite square, also known as granite square, is mainly composed of minerals such as plagioclase, plagioclase, small amounts of olivine, biotite, and trace amounts of magnetite. It has a black color and a precise structure. After billions of years of aging, it has a uniform texture, good stability, high strength, and high hardness, and can maintain high accuracy under heavy loads. Suitable for industrial production and laboratory measurement work.

　　Advantages of granite square ruler:

　　1. The rock undergoes long-term natural aging, and the internal stress completely disappears without deformation, resulting in high accuracy.

　　2. Not afraid of acid and alkali erosion, not prone to rust, does not require oil, is not prone to sticking fine dust, maintenance is convenient and simple, and has a long service life.

　　3. There will be no scratches, not hindered by constant temperature conditions, and the temperature measurement accuracy can be maintained at room temperature.

　　4. Non magnetized, able to move smoothly during measurement, without any sluggishness, unaffected by moisture, and well balanced on a flat surface

　　Granite square is a coarse-grained or medium grained intrusive rock rich in quartz and feldspar. It is a common plutonic rock in the crust, formed by cooling magma deep in the crust. Used for detection, measurement, marking, equipment installation, and industrial engineering construction. Due to its characteristics of being difficult to magnetize, wear-resistant, acid and alkali resistant, unchanging, easy to clean, and not rusting.

　　Where the granite square is insufficient:

　　Marble square rulers are relatively brittle compared to cast iron square rulers. After being bumped, there will be pits, and more pits will affect their accuracy and use. The marble right angle ruler is mainly used to detect the straightness and verticality of workpieces. The stone used has the characteristics of tight structure, good stability, uniform texture, high hardness, and high strength. The matching marble measuring tools include marble parallel gauges, marble square rulers, marble square cylinders, etc.