Pulite Company teaches you how to choose the grade of U-bolts

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　　Pulite Company will show you how to choose the grade of U-bolts. U-bolts are among the most common hardware products in our daily lives, playing a very important role in them. Today, Pulite Company will explain how to select the appropriate grade for U-bolts. 　　Bolt grades are mainly divided into high-strength bolts and ordinary bolts. 　　High-strength materials are primarily used in applications such as outdoor projects, wind power systems, or mechanical devices that require mobility; they have a high tensile strength. Ordinary bolts are sufficient for use in smaller machinery, such as turbines. The choice of material depends on the application environment and operating conditions, and high-strength bolts are being used more and more frequently. The two common strength grades are 8.8s and 10.9s, with grade 10.9 being more prevalent. The strength grades of ordinary bolts are lower, generally at 4.4 grade, 4.8 grade, 5.6 grade, and 8.8 grade. 　　1. [From the perspective of raw materials]: High-strength bolts are made from high-strength materials. The shank, nut, and washer of high-strength bolts are all made from high-strength steel, with grades such as 45 steel, 40 boron steel, and 20 manganese-titanium-boron steel being commonly used. Ordinary bolts are commonly made of Q235 steel. 　　2. [In terms of strength grade]: High-strength bolts are being used more and more widely. The two common strength grades are 8.8s and 10.9s, with grade 10.9 being more prevalent. The strength grades of ordinary bolts are lower, generally at 4.4 grade, 4.8 grade, 5.6 grade, and 8.8 grade. 　　3. [From the perspective of force characteristics]: High-strength bolts apply pre-tension and transmit external forces through friction. In ordinary bolt connections, shear force is transmitted through the shear resistance of the bolt shank and the compressive strength of the hole walls; when the nut is tightened, a very small pre-tension is generated, whose effect can be ignored. In contrast, high-strength bolts not only have high material strength but also exert a large pre-tension on the bolts, resulting in compression between the connected components and thus generating significant friction perpendicular to the direction of the bolt shaft. Moreover, the pre-tension, the slip resistance coefficient, and the type of steel all directly affect the load-bearing capacity of high-strength bolts. 　　4. [In terms of usage]: For the bolted connections of the main structural components in buildings, high-strength bolts are generally used. Ordinary bolts can be reused, while high-strength bolts cannot. High-strength bolts are generally used for permanent connections. High-strength bolts are prestressed bolts; for friction-type bolts, a specified prestress is applied using a torque wrench, while for compression-type bolts, the hex head is removed. Ordinary bolts have poor shear strength and can be used in secondary structural components. Ordinary bolts only need to be tightened.