Service Hotline1. For low strength (below 500 N/mm2 or below 60000 psi) bolts use general soft steel, generally use SAE 1008 or JIS SWRM 8 (or SWRCH 8). 2. Lower strength (600 N/mm2 or 74000 psi) ) bolts use general soft steel, but limited carbon content grade, generally use SAE 1010 - 1015 or JIS SWRM 10 - 15 (or SWRCH 10 - 15). .3. Higher strength ( 800 N/mm2 or 125000 psi ) bolts of medium carbon steel, low carbon boron steel plus quenching and tempering, generally use SAE 1035 - 1040 or SWRCH 35K - 40K. 4. High strength (900 N/mm2 or more or 150000 psi or more) bolts use medium carbon Alloy steel or low carbon boron steel, in terms of application, if the metric Class 10.9 uses low carbon boron steel, the imprint should be added under the series imprint to become 10.9, and the imprint of the inch 8.2 grade is also used with the general Grade 8 bolts The imprint is different for easy identification. High-strength bolts made of low carbon boron steel cannot be used in high temperature conditions. The design strength exceeds Class 12.9 or ASTM A574 ultra-high strength bolts are limited to medium carbon alloy steel plus quenching and tempering. The performance grades of bolts for steel structure connection are divided into more than 10 grades such as 3.6, 4.6, 4.8, 5.6, 6.8, 8.8, 9.8, 10.9, 12.9, etc. Among them, the bolts of grade 8.8 and above are made of low-carbon alloy steel or medium-carbon steel and are heat-treated (quenching, tempering), commonly known as high-strength bolts, the rest are commonly known as ordinary bolts. The bolt performance grade label consists of two parts of numbers, which represent the nominal tensile strength value and yield ratio of the bolt material respectively. For example, a bolt with a performance level of 4.6 means: 1. The nominal tensile strength of the bolt material is 400MPa; 2. The yield ratio of the bolt material is 0.6; 3. The nominal yield strength of the bolt material is 400×0.6=240Mpa . Performance level 10.9 high-strength bolts, after heat treatment, can achieve: 1. The nominal tensile strength of the bolt material is 1000MPa; 2. The yield ratio of the bolt material is 0.9; High-strength bolts, processing and manufacturing problems are compared Small, general fastener manufacturing companies can master the manufacturing process; but problems are prone to occur in material selection and heat treatment. Material selection is the primary link. Various alloying elements have a great influence on the properties of the material, and the material must be subjected to spectral composition analysis; secondly, the fracture problem and the choice of heat treatment process have a great influence and are very important. Dealers and traders must control the inspection and performance testing links; automotive fasteners have high requirements and must carefully control the quality.
The traditional gasket is a single-piece gasket that works independently. This gasket mainly relies on friction to achieve the anti-loosening effect. The new washer is composed of two pieces. Its unique embedded structure changes the way that the traditional washer mainly achieves anti-loosening through friction. Instead, it adopts the most advanced anti-loosening technology in the world and uses the tension between the two gaskets to achieve. The dual effect of anti-loosening and tightening.
The shear strength of a metal material refers to the ability of the material to withstand shearing force, which refers to the strength of the external force perpendicular to the material axis and shearing the material. The test is usually to install the cylindrical pin into the specified fixture, and the gap between the supporting part and the loading part is required to be no more than 0.15mm, and then force is applied to test the shear strength of the material.
Countersunk rivet is a kind of part that uses its own deformation or interference connection to connect and position two objects in riveting. It is widely used in automobiles, vehicles, electromechanical products, aerospace products and other fields. When the countersunk head rivet is used, the head of the rivet sinks into the connected parts in whole or in part. This structure is mostly used for parts that require a smooth and smooth appearance. The standard structure of countersunk head rivets is specified in the national aviation standard, national standard and national standard, and the countersunk head rivets involved in these standards are all standard rotary structures.
With the vigorous development of the construction market, fastener-type steel pipe scaffolding and formwork support have been widely used, and a large number of fasteners are used in the fastener-type steel pipe scaffolding and formwork support system. The commonly used fastener structure generally includes a fastener body 1, a blade 2, and a rivet 3 for connecting the fastener body and the blade. An arc-shaped cavity 4 for penetrating the steel pipe is provided between the fastener body and the blade. Figure 1 Right-angle fasteners shown. However, in the process of building construction, the blades of the fasteners have different degrees of cracks and fractures, which lead to the scrapping of the fasteners, or the fasteners are scrapped due to the poor anchoring of the rivets of the fasteners, resulting in a lot of waste, and the fasteners are damaged. There is a large safety construction hazard. However, repairing damaged fasteners entirely by hand has many disadvantages, such as technical difficulty, time-consuming and labor-intensive, and high operating costs. Therefore, researching and designing an auxiliary device for installing rivets in the process of repairing damaged fasteners to reduce labor intensity of workers, improve repair efficiency, and reduce operating costs is a technical problem to be solved urgently by those skilled in the art.
We have many years of experience in the production and sales of screws, nuts, flat washers, etc. The main products are: blackened round head screws, double-headed screws, lifting ear straps, cap nuts and other products, we can provide you with suitable fastening for you. piece solution.
