U-bolt, as non-standard parts, is U shaped so-called U type bolt. Nut and thread ends can be combined, mainly used for fixed tubular objects such as pipes or sheet material or automobile leaf spring. Due to the fixed objects like people on horseback, so it also called horse bolts.
According to thread length it is divided into two types of full thread and non-full thread. The threaded teeth are classified into two groups: coarse and fine, and the coarse tooth type does not appear in the sign of the bolt.
According to performance rating of 3.6, 4.8, 5.6, 5.8, 8.8, 9.8, 10.9, 12.9 and eight grades, bolt includes more than 8.8 (including 8.8) bolt material for low carbon alloy steel or carbon steel by heat treatment (quenching and tempering), high strength bolts. The following grade 8.8 is known as the common bolt.
According to the production accuracy ordinary bolts can be divided into A, B, C three grades, A and B class for refined bolts, C grade for coarse bolts. For connection bolts of steel structures, unless otherwise specified, they are generally plain, C grade bolts.
There are differences in the processing methods of different grades, and the corresponding processing methods are as follows:
The bolt bars of A and B grade bolts are machined by the lathe. The surface is smooth, the dimension is exact, and the material performance grade is 8.8. The manufacture and installation is complicated, the price is higher, and it is seldom used;
C grade bolts are made of raw round steel, the size is not precise, and the material performance grade is 4.6 or 4.8. When shearing joint, the deformation is large, but the installation is convenient, the production cost is low, and the utility model is mainly used for temporary fixing when the tension joint is connected or installed.