There are many mechanical parts in our lives. Bolts are a kind of mechanical parts, which are mainly used in conjunction with nuts and belong to a kind of fixed parts. There are many types of bolts with different specifications, which need to be used with different nuts. Most of the bolts are made of stainless steel, and some bolts are made of other metals. Bolts are a kind of hardware parts and are also a relatively common hardware accessory.
The following editor will recommend the classification of bolts for everyone.
1. Classification
According to the force mode of the connection, it is divided into ordinary and reamed holes. According to the shape of the head: there are hexagonal head, round head, square head, countersunk head and so on. The hexagonal head is the most commonly used. The countersunk head is generally used where connection is required.
1. Riding bolt
The English name of the riding bolt is U-bolt, which is a non-standard part. The shape is U-shaped, so it is also called U-bolt. Both ends have threads that can be combined with nuts. They are mainly used to fix tubular objects such as water pipes or sheet objects such as car plates. The spring is called a riding bolt because it fixes the object in the same way as a person is riding on a horse.
2. According to the thread length, it is divided into full thread and non-full thread.
According to the thread type, it is divided into two types: coarse thread and fine thread. The coarse thread type is not displayed in the bolt mark.
Bolts are divided into eight grades: 3.6, 4.8, 5.6, 5.8, 8.8, 9.8, 10.9, and 12.9 according to their performance grades. Among them, bolts of grade 8.8 and above (including grade 8.8) are made of low-carbon alloy steel or medium-carbon steel and are heat treated (quenched). + Tempering), generally referred to as high-strength bolts, generally referred to as ordinary bolts below grade 8.8 (excluding grade 8.8).
3. Ordinary bolts can be divided into three grades: A, B, and C according to the production accuracy. Class A and B are refined bolts, and Class C is coarse bolts. For connecting bolts for steel structures, unless otherwise specified, they are generally ordinary crude grade C bolts.
There are differences in the square hair of different levels of processing, and the corresponding processing methods are usually as follows:
①The bolts of grade A and B bolts are machined by a lathe, with smooth surface and precise size. The material performance grade is 8.8, the production and installation are complicated, and the price is relatively high, so it is rarely used; ②The grade C bolts are made of unprocessed round steel. The size is not accurate enough, and the material performance level is 4.6 or 4.8. Large deformation during shear connection, but convenient installation and low production cost, it is mostly used for tensile connection or temporary fixation during installation.
The above is the introduction of the classification of bolts. The fixing effect of bolts is better, but different types of bolts have different uses. When choosing bolts, you also need to choose according to mechanical properties. Parts with different mechanical properties need different fixing bolts.
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