【Summary】Hardware standard parts, there are some fasteners are called bolts, some fasteners are called screws, and some fasteners are called studs, so what are the differences, they refer to the same product? Is it possible to call a bolt a screw or a stud at will? Today's article, I will mainly call the bolt products listed, do a detailed analysis, so you know what is the bolt, the bolt and what uses, and other products called this screw or stud, I will use a separate article to analyze. We start with the common bolts.
Hardware standard parts, there are some fasteners are called bolts, some fasteners are called screws, and some fasteners are called studs, so what are the differences, they refer to the same product? Is it possible to call a bolt a screw or a stud at will? Today's article, I will mainly call the bolt products listed, do a detailed analysis, so you know what is the bolt, the bolt and what uses, and other products called this screw or stud, I will use a separate article to analyze. We start with the common bolts.
Hexagonal head bolts - hexagonal head bolts is also commonly known as hexagonal bolts, it can be said that every enterprise in the production of it, the standard is GB/T5782 or GB/T5783, 5782 standard means half tooth, 5783 standard means full tooth, its production range from M5 mm to M64 mm can be provided, and are available in stock, the material is based on the actual requirements of their own The material is according to the actual requirements, the level can be 4.8, 8.8, 12.9, etc., can also choose stainless steel 304 or 316 material. Of course there are other hexagonal head bolts such as copper, but they are really not commonly used, it is only the material that is different, the production standards are the same, hexagonal head bolts can be surface plated. There is another type of bolt with a fine thread in the standard hexagonal head, the head shape is the same and the difference is only in the fine thread.
Hexagon bolts with slots - It has a slot in the regular hexagon head bolts, the use of this slot is that you can use a word screwdriver to install it, mainly because some installation environment is difficult, when the bolt is tightened, the hexagon head tools can not be put down, only the use of a word screwdriver to make some micro-adjustments.
Cross-slotted hexagonal head bolts - This is the same as the above one-slotted hexagonal head bolts, except that the one-slotted slot is replaced by a cross-slotted slot. The cross-slotted design is more user-friendly and easy to install with power tools, while the one-slotted slot is somewhat prone to slipping with power tools. The cross slotted hexagonal head bolts are sometimes combined with flat pads and spring pads to make a hexagonal head combination bolt.
Hexagon head bolts with holes - This is a small hole punched in the head of the standard bolt, this small hole is used to put a cotter pin on it at a later stage, some also have a small hole punched in the end, also to add a cotter pin for use, mainly to prevent loosening.
Hexagon head bolts with hinged holes - although they are also hexagon head bolts, they are completely different from ordinary hexagon head bolts, the difference lies in the word hinged holes. It has a thicker light rod section than the threads, whereas the standard one is the same, and the light rod section needs to be ground without a core before it is used. As an example, if a reamed hole bolt, which has a M12 thread, has a straightforward light bar of 16 mm, is it very different from a conventional hexagonal bolt. On the standard GB/T27 reamed bolt, there is also a reamed bolt with a hole, that is, on the original basis, a small hole is punched at the end of the thread, the principle is also to add a cotter pin later to prevent the bolt from coming loose.
Hexagonal flange bolts - this should be more common, it is the standard hexagonal head bolts below, and an additional circle of flange design, to increase the contact area of the bolt head, to strengthen the friction coefficient, so as to achieve better locking performance.
The square head bolt is not a hexagonal head, it is a quadrilateral shape, similar to the T-bolt, except that the T-bolt is a bit beveled, while the quadrilateral bolt is a positive quadrilateral head type.
The square head round neck bolt, also known as a carriage bolt, has a round head and in order to be able to facilitate installation and locking, there is an additional quadrangular column underneath the round cap as a way to snap in the slot to prevent the bolt from turning coaxially during installation. The foot bolt is a fastener buried in the ground, it has a 7-word head and a 9-word head, mainly used for the positioning of equipment installation, belongs to a large bolt products.
Introduction to bolt strength classes
Strength grades are classified according to mechanical properties. According to the relevant standards, the bolt performance grade is divided into 3.6, 4.6, 4.8, 5.6, 6.8, 8.8, 9.8, 10.9, 12.9 and more than 10 grades, of which 8.8 and above bolts made of low-carbon alloy steel or medium carbon steel and heat treatment (quenching, tempering), commonly known as high-strength bolts, the rest are commonly known as ordinary bolts. The bolt performance grade number has two parts consisting of numbers, which indicate the nominal tensile strength value of the bolt material and the flexural strength ratio. For example.MORE +
The first is the punching of the head, where the head of the screw is punched out of the wire and the wire is cut. The second is thread rolling, where two files are used to thwart the threads on top of the previous process.MORE +
Performance grades for hexagonal flange bolts
The bolt performance grade is composed of two numerical parts, which indicate the nominal tensile strength value and the flexural strength ratio of the bolt material.MORE +
What are the common automotive fasteners
Generally we use most of the fasteners belong to the type of general-purpose parts, its standard type is still quite high, the common fastener parts are the following 12 kinds:MORE +