Service HotlineAt present, when fastening parts on thin-walled products or thin plates in our country, screws are usually used to fasten, and welding nuts are required to make the thin plate easy to burn through, or the objects are drilled and tapped to connect, so that the product is deformed and the connection strength is not strong. , It cannot be fastened on some equipment, the operation is inconvenient, and the production efficiency is low.
People often think that magnets attract stainless steel to verify its pros and cons and its authenticity. If it does not attract non-magnetism, it is considered to be good, and it is genuine; if it is magnetic, it is considered to be counterfeit. In fact, this is an extremely one-sided, unrealistic and wrong identification method. There are many kinds of stainless steel screws, which can be divided into several categories according to the organizational structure at room temperature: 1. Austenite type: such as 304, 321, 316, 310, etc.; 2. Martensite or ferrite type: such as 430, 420, 410, etc.; Austenite type is non-magnetic or weakly magnetic, and martensite or ferrite is magnetic. Most of the stainless steel usually used for decorative tube sheets is austenitic 304 material, which is generally non-magnetic or weakly magnetic, but may also appear magnetic due to fluctuations in chemical composition or different processing conditions caused by smelting, but this cannot be considered as a Counterfeit or substandard, what is the reason for this? As mentioned above, austenite is non-magnetic or weakly magnetic, while martensite or ferrite is magnetic. Due to component segregation or improper heat treatment during smelting, a small amount of martensite or ferrite in austenitic 304 stainless steel will be caused. body tissue. In this way, 304 stainless steel will have weak magnetism. In addition, after cold working of 304 stainless steel, the structure will also be transformed into martensite. The greater the cold working deformation, the more martensite transformation, and the greater the magnetic properties of the steel. Like a batch of steel strips, Φ76 tubes are produced without obvious magnetic induction, and Φ9.5 tubes are produced. The magnetic induction is more obvious due to the large deformation of the bending and bending. The deformation of the square rectangular tube is larger than that of the round tube, especially the corner part, the deformation is more intense and the magnetic force is more obvious. In order to completely eliminate the magnetic properties of 304 steel caused by the above reasons, the stable austenite structure can be restored by high-temperature solution treatment, thereby eliminating the magnetic properties. In particular, the magnetic properties of 304 stainless steel caused by the above reasons are completely different from those of other materials such as 430 and carbon steel, which means that the magnetic properties of 304 steel always show weak magnetic properties. This tells us that if the stainless steel strip is weakly magnetic or completely non-magnetic, it should be judged as 304 or 316 material; if it is the same as carbon steel, it shows strong magnetism, because it is judged as not 304 material.
In the non-standard mechanical design, when the middle part of the long shaft or rod-shaped structure needs to be threaded, the end is limited and the nut cannot be penetrated, which will cause the problem that the installation cannot be realized. In order to solve this problem, it often has to be cancelled. It is not conducive to the realization of equipment cost reduction and optimal function, and even the problem cannot be solved, and another way out is needed.
Most of the blind hole installation rivets have the characteristics of light weight, reliable connection, high strength, and convenient and quick installation. For example, blind rivets have been widely used in various aerospace vehicles.
Standards are norms, and each country and sector has its own standards. GB—Chinese National Standard (National Standard) ANSI—American National Standard (American Standard) DIN—German National Standard (German Standard) ASME—American Society of Mechanical Engineers Standard JIS—Japanese National Standard (Japanese Standard) BSW—British National Standard GB—National Standard The standard is one of the many standards in my country, and there are also industry standards, professional standards and department standards. National standards are divided into: GB (mandatory standards) and GB/T (recommended standards) and GBn (national internal standards) and so on. We usually see GB30, GB5783, etc. are mandatory standards. In addition to some basic dimensions such as head-to-side, head thickness, etc., the above standards are mainly different in the threaded part. The threads of GB, DIN, JIS, etc. are all in MM (millimeters), which are collectively referred to as metric threads. Another thread like ANSI, ASME, etc. is called American standard thread in inches. In addition to metric threads and American threads, there is also a BSW-imperial standard, whose threads are also in inches, commonly known as Wyeth threads. In the usual domestic sales business, the most common standards we encounter are GB (National Standard) and DIN (German Standard). In terms of production products, the following standards are mainly encountered: GB30; GB5783; GB5782; GB52; GB6170; GB818; GB819; GB845; GB846; GB70; DIN912; DIN933; DIN931 and so on. GB30 (old national standard) has been replaced by GB5783 (new national standard) in the standard book. GB52 (old national standard) has been replaced by GB6170 (new national standard) in the standard book.
We have many years of experience in the production and sales of screws, nuts, flat washers, etc. The main products are: sealing washers, tubular rivets, single-headed stud bolts, double-headed plastic pillars and other products, we can provide you with suitable fastener solutions for you Program.
