High Strength 1/2-1 1/2 Carbon Steel Black Oxide ASTM A490 Hex Cup Bolts

High Strength 1/2-1 1/2 Carbon Steel Black Oxide ASTM A490 Hex Cup Bolts

Description

American-made A325 high strength screw screw A490 high strength bolt (HSBs). Material: A325 A490 A449 Product categories: American A325 bolts TYPE 1 A490 bolts according to standard: specification: 1 / 2 1 / 1 / 2. Between ASTM high strength bolts applicable: 1: American-made A325 TYPE1 carbon content. Carbon boron or medium carbon alloy steel, suitable for general steel structures, available for hot dip galvanizing... American A325 TYPE2 1991/11.TYPE3 weathering steel. Weathering resistance equivalent to A242 / A566 / A709 and other steels. Suitable for use with weathering steels. Can be hot-dip galvanized. 2: American A490 TYPE1. Bolts are made of alloy steel. Nominal diameter 1/2 "1 1/2", suitable for general steel structure, not hot-dip galvanized. American A490 TYPE2 bolts are usually made of low carbon bada loose iron steel. Nominal diameter 1/2 "1 1/2", not hot-dip galvanized. American A490 TYPE3 weathering steel, weathering resistance equivalent to A2422.A588 / A709 and so on. Suitable for use with weathering steel. Not hot-dip galvanized three: American A449 TYPE1 carbon content. Nominal diameter is 1/4 "3". Suitable for general steel structure, it can be used for high temperature resistance, can be hot-dip galvanized. American made of A449 TYPE2 low carbon hematite loose iron steel. Nominal diameter is 1/4 "1". Non-hot-dip galvanizing-Table 1: minimum pretension bolts nominal diameters for ASTM A325 and ASTM A490 bolts) minimum pretensile force TB / tf)

Several concepts about high strength bolts 1. According to the specification of bolt performance class 8.8 or above, called high strength bolt. The current national standard only listed to M39, for large size specifications. In particular, the length of 15 times the length of high-strength bolts, domestic production is still short.

Distinction between high strength bolts and ordinary bolts:

High-strength bolts are larger than ordinary bolts of the same specification.

The material for ordinary bolts is made of Q 235 (A 3).

High strength outer hexagon bolt

High-strength bolt material 3 steel or other high-quality materials, made after heat treatment, improve the strength.

The difference between the two is the difference in the strength of the material.

From the perspective of raw materials:

The high strength bolt is made of high strength material. The screw, nut and gasket of high strength bolt are made of high strength steel. 35CrMoA, etc. Common bolts are made of Q235 steel (equivalent to A 3 in the past).

In terms of strength:

High strength T-groove bolt

High strength bolts are widely used. Two strength grades of 8.8s and 10.9s are commonly used, of which 10.9 grade is the majority. Ordinary bolts have a low strength grade of 4.4 grade or 4.8 grade. Levels 5.6 and 8.8.

From the point of view of stress characteristics: high strength bolts apply pretension force and transfer external force by friction. Ordinary bolts connect by bolt shear resistance and hole wall pressure to transfer shear force, and the pre-tension force is very small when the nut is tightened. In addition to the high strength of the material, the high strength bolt exerts a large pretension force, which causes the extrusion force between the connecting members and makes the friction force perpendicular to the screw direction very large. The bearing capacity of high-strength bolts is directly affected by pretension, slip resistance and steel type.

Specification:

Application:

The material of high strength bolt is different from that of ordinary bolt. High strength bolt is generally used for durable connection. Commonly used are M16 / M30. The performance of super high strength bolt is unstable. The bolted connections of the main members of the building structure should be used with caution. High strength bolts are generally used to connect. 5. High strength bolts from the factory do not distinguish between bearing type and friction type. 6. Whether it is friction type high strength hexagon bolt and bearing high strength bolt. In fact, there are differences in design and calculation methods: (1) friction type high strength bolts take sliding between plates as the limit state of bearing capacity.Sliding between as the normal use limit state, and joint failure as the ultimate load capacity state. 7. Friction high strength bolt can not give full play to the potential of the bolt. In practical application. For very important structures or structures subjected to dynamic loads, especially when the reverse stress is caused by load, friction type high strength snails should be used. The untapped bolt potential may be used as a safety reserve at this time. In addition, high strength bearing bolts should be used to reduce the cost.

Advantage:

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High strength bolt connection has the advantages of simple construction, good mechanical performance, detachability, fatigue resistance, and no loosening under dynamic load. It is a promising connection method.

A high - strength bolt is a special wrench to tighten the nut , so that the bolt generates a large and controlled pre - tension , and the same size of pre - pressure is generated by the connecting piece through the nut and the backing plate .

The high strength bolt connection depends on the friction between the contact surfaces to prevent the joint from sliding, so as to make the contact surface have enough friction. It is necessary to increase the clamping force of the member and the friction coefficient of the contact surface. The clamping force between the components is realized by applying the pretension force to the bolt, so the bolt must be made of high strength steel. This is also known as high-strength bolt connections.

High strength bolt connection, greatly affect the size of the coefficient of friction of bearing capacity. The results show that the friction coefficient is mainly affected by the material form and the effect of contact component. In order to increase the friction coefficient of the contact surface, the construction should be often used for sand blasting, to solve contact elements in the area connecting surface with a wire brush cleaning method.

More pictures:

Jiaxing Haina Fastener co. Ltd was established in 2010, located in the hometown of fasteners jiaxing city. For many years of export experience, our products has been best-selling in Europe, the United States, the Middle East and Southeast Asia. The products are manufactured by more functions machine, which is brought in domestic and foreign well-known enterprises. The products made are fully compatible with the international standards, well received by domestic and foreign customers. Through scientific management, Jiaxing Haina fastener Ltd company has been obtained ISO9000 certificate of Quality Managerment System, SGS and BV international certificate system of Make in China.

Product standards including DIN, ISO, GB and ASME/ANSI, BS, JIS AS. Main levels of carbon steel: 4.8, 4.8, 6.8, 8.8, 10.9, and 12.9 grade, the main material of stainless steel SS201, SS304, SS316 and various kinds of special stainless steel.

The width range of our products can be divided into auto fasteners, mechanical fasteners, construction fasteners, power fasteners, railway fasteners, household electrical appliances fasteners and chemical fasteners,

We have first-class service team, so we can meet the different requests for a set of customers. We solemnly commitment, first-grade quality, timely delivery guaranteed

Reasonable price and service paramount, forward to the operation principle of quality first and customer first, pursuit of excellence to create first-class brand, our aim is brand promoting development, management promoting earnings, warmly greeting home and abroad new and old customers to communicate and cooperate to seek greater success and brilliant future.