Service Hotline2. Low cycle fatigue Low cycle fatigue means that the fatigue stress is close to or exceeds the yield limit of the material. The material has a certain amount of plastic deformation in each strain cycle. The life is generally in the range of 102 to several times 104, and the fatigue curve is generally used. ε-N curve representation. The finite element calculation results show that after the bolt is screwed into the lock nut, the stress at the root of the threaded piece is large, and part of the surface area is in a yield state, while the strain in the central area of the root of the threaded piece is small, and the strain situation is more complicated. The area with high strain at the root of the thread piece experiences reciprocating loading, which is prone to low cycle fatigue, which reduces the pressure of the thread piece and reduces the screw-out torque.
spring washer is installed under the nut to prevent the nut from loosening. It is stated in the national standard. Hexagonal slotted nuts are specially designed for use with bolts with holes at the end of the screw, so that the cotter pin can be inserted into the hole of the screw from the groove of the nut to prevent the nut from automatically loosening. It is mainly used for vibration loads or alternating loads. . The methods to prevent the nut (or bolt) from automatically loosening in the mechanical design and production are as follows: 1. Add a spring washer; (simple and easy to do) 2. Use a hexagonal slotted nut + a split pin; (increase the processing process) 3 . Pad the stop washer; (increase the processing process compared with the same period of last year) 4. Insert the steel wire into the hexagon head opening of the hexagon bolt. (Increased processing steps compared to the same period of last year) Spring washers are used to prevent loosening. For example, the bolts connecting the motor and the machine base generally need to add spring washers, because the motor vibrates without the spring washers, and the nuts will loosen. Generally, the fasteners on the equipment with vibration There is a spring gasket on it, and there is generally no need to add a gasket on the flange! Whether the spring gasket is added to the flange is related to the medium circulating in the pipeline. If it is easy to generate pulses, it is best to add spring gaskets, as well as high-speed fluid, and the caliber changes frequently. Do not generalize. On some valves, the stuffing box gland All flanges need to be added with spring gaskets. The automatic selection of spring gaskets is included.
The inch thread is the thread size marked in inch. According to the shape, it is divided into two types: cylindrical and conical; according to the tooth angle, it is divided into two types: 55° and 60°. The 1/4, 1/2, 1/8 marks in the thread refer to the diameter of the thread size in inches. One inch equals 8 cents, 1/4 inch equals 2 cents, and so on.
The material of the round head three combination screw is divided into iron and stainless steel. The iron ones are made of different iron screw wires. Generally, the wire of the combination screw is 1010, 1018, 10B21 and so on. 10B21 is used to make 8.8 grade combination screws. Like 8.8-grade socket head cap screws, 10B21 wires are often used to make them. When done, go to heat treatment. After heat treatment, remove hydrogen and electroplating. This is to prevent the spring washer of the socket head cap screw from breaking. Stainless steel combination screws, in the combination screw market, generally refer to stainless steel SUS304 combination screws. 201 combination screws generally do very little. Few manufacturers of round head three combination screws produce 201 combination screws. Because the hardness of the screw wire of stainless steel 201 is not well controlled, it is easy to produce cracks. Introduction to the basic knowledge of electroplating round head combination screw electroplating generally refers to the de-plating of iron combination screws. Electroplating is divided into environmental protection and non-environmental protection. Commonly used combination screw electroplating colors include green color zinc, green blue zinc, green white zinc, green nickel, red color, white zinc, white nickel, etc. Cross recessed combination screws, hexagon combination bolts and self-tapping combination screws are used in the same way as the corresponding cross recessed screws, hexagon head bolts and self-tapping screws. The main feature of these combination screws is that they are equipped with corresponding washers, which are very convenient to use.
In order to achieve the above purpose, Yueluo provides the following technical solutions: threaded rivets include a nail rod, an expansion piece, and a nail sleeve, one end of the nail rod is provided with a mounting piece, and the side of the mounting piece away from the nail rod is movably installed with a mounting piece. There is a driving mechanism. The driving mechanism includes a mounting cylinder and a movable rod. A cross groove is formed at one end of the mounting piece close to the driving mechanism. The rod is movably installed on the inner side of the installation cylinder, and one end of the movable rod close to the cross groove is fixedly provided with a cross connecting piece that matches the cross groove, the cross connecting piece is matched with the cross groove, and the movable rod is far away from the cross groove. One end of the cross connecting piece is fixedly provided with a fixing piece, the fixing piece and the installation cylinder are screwed together by threads, the expansion piece is sleeved on the outer side of the nail rod, and the nail sleeve is movably installed on the nail rod away from the driving mechanism The outer side of one end of the nail rod is movably installed with a fixing mechanism.
We have many years of experience in the production and sales of screws, nuts, flat washers, etc. The main products are: inner stop gasket, gasket material, PWM bolts with flat washers, riveting screw sleeves with an outer diameter of 7.2SOO and other products, we can provide products such as You have the right fastener solution for you.
