Service Hotline1. Standards for fastener product dimensions: specify the content of the basic dimensions of the product; threaded products also include the basic dimensions of the thread, thread end, shoulder distance, undercut and chamfer, and the end of externally threaded parts size, etc. 2. Standards for technical conditions of fastener products. It mainly includes product tolerances, mechanical properties, surface defects, surface treatment, product testing standards and corresponding specific provisions. 3. Standards for screw product acceptance inspection, marking and packaging: specify the qualified quality level and sampling plan of random inspection items during product acceptance inspection, as well as product marking methods and packaging requirements. 4. Marking method standards for standard parts, fasteners, screws and screws: specify the content of the complete marking method and simplified marking method of the product. 5. Standards for other aspects of fasteners: such as standards for fastener terminology, standards for fastener product weight, etc.
With the development of the economy, automobiles have become an indispensable means of transportation in people's lives, and the production, sales and after-sales services of automobiles have also developed rapidly. Automobile wheels and steel rings are an important part of auto parts and are also related to The use of the car is safe. The connection between the car wheel and the steel ring is realized by bolts, so the bolts and nuts need to have good fixation.
screw is a tool that uses the physical and mathematical principles of the circular rotation and friction of an object to fasten the parts of the object step by step. Since the parts to be fixed are different, different types of screws are required for different applications. Press screw is a new type of fastener applied to thin plate or sheet metal. The principle is to press the embossed teeth into the preset holes of the sheet metal. The diameter of the general preset holes is slightly smaller than the outer diameter of the pressure riveting screw. The periphery of the hole is plastically deformed, and the deformed object is squeezed into the guide groove, thereby producing a locking effect. However, the existing pressing screws are easy to loosen due to long use time or frequent vibrations, which is prone to certain hidden dangers.
screw grooving device comprises a workbench, a vibrating plate is arranged on the upper part of the workbench, a conveying device is arranged below a discharge port of the vibrating disc, the slotting device is arranged on one side of the conveying device, and the slotting device is provided with a reciprocating device. When the movement is extended, the cutting wheel can be used for grooving the screws in the conveying device, and the grooving device is also fixedly provided with a fixed wheel for grinding the grooved screws.
(1) The screw-in performance test is to screw the self-tapping locking screw sample into the test plate until one complete thread completely passes the test without breaking. (2) The destructive torque test is to clamp the stem of the self-tapping locking screw specimen in a thread mold or other device that matches the screw thread, and uses a calibrated torque-measuring device to measure the screw. Torque is applied until fracture, which should not occur in the clamped threaded portion. (3) Carry out a tensile test on the screw sample to check the minimum tensile load for failure. The fracture should be within the length of the rod or the unthreaded thread, and should not occur at the junction of the nail head and the rod. Before the sample breaks, it should be It can reach the minimum tensile load specified by the corresponding performance class. (4) Hydrogen embrittlement is a problem that must be strictly paid attention to in the surface treatment process of self-tapping locking screws. In the pickling process, the screw is stirred in dilute hydrochloric acid, and the amount of hydrogen absorbed by the pickling steel increases linearly with the square root of time and reaches the saturation value. Less than 100%, a large number of hydrogen atoms will be produced, which will be attached to the surface of the screw, resulting in hydrogen infiltration, and the steel will become brittle due to the absorption of hydrogen. The self-tapping locking screw takes 6~8h to drive hydrogen, and the temperature is 160~200℃ (phosphating) and 200~240℃ (electroplating). However, in the production process, the hydrogen drive time should be determined according to many production conditions such as core hardness, surface roughness, electroplating time, coating thickness, pickling time, and acid concentration. It is best to do it before passivation and just after electroplating.
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