Specification and representation of bolts Which bolts are a common fastener used in household and industrial machinery. Choosing the right bolt requires understanding its specifications and representation. The specification, type, representation, classification and structure of bolts will be introduced in detail in this paper.
The specification of the bolt refers to its size, including length, diameter and thread length and diameter. Bolt length is generally expressed in millimeters. Diameters are expressed in two ways: millimeters and inches. Thread length and diameter are also expressed in two ways: millimeters and inches. There are four main types of bolts: standard bolts, thin-walled bolts, hand-pulled bolts and nuts. Standard bolts are the most common, with round threads and heads, and are suitable for a variety of situations. Thin wall bolts have flat threads and heads for applications where compact construction is required. Hand pull bolts are suitable for fixing flexible materials. Nuts are used to hold bolts. The expression method of the bolt is to indicate its specification and model with four English letters. The first letter indicates the bolt material, the second letter indicates the bolt shape, the third letter indicates the thread shape, and the fourth letter indicates the bolt type. For example,A2-70 represents A standard bolt of material A, shape 2, and thread 70.
Bolts can be classified according to material and structure. According to the material can be divided into stainless steel bolts, carbon steel bolts, aluminum alloy bolts, wood bolts and plastic bolts. Stainless steel bolts are corrosion-resistant and have high strength. Carbon steel bolts are cheap. Aluminum alloy bolts are light and corrosion-resistant. Wood bolts are light and cheap. Plastic bolts are light and cheap. According to the structure can be divided into inch thread and metric thread, and round head, flat head and countersunk head. The structure of the bolt is composed of the thread and the head shape. There are two kinds of thread, imperial thread and metric thread. There are three kinds of head: round head, flat head and countersunk head. The imperial thread is a straight line with pitch, and the metric thread is an arc with pitch. The round head is round, the flat head is flat, and the countersunk head is deeper than the round head. In short, understanding the specification and representation of bolts is crucial to choosing the right bolt. Different types of bolts are suitable for use in different occasions. Understanding the classification and structure of bolts is also a prerequisite for using bolts. In practical applications, we choose the right bolt based on factors such as the required fastening force and the environment in which it is used.
