Standard Specification for Screws in the Fastener Industry

For non-products, the following standards will be mainly touched: GB30; GB5783; GB5782; GB52; GB6170; GB818; GB819; GB845; GB846; GB70; DIN912; DIN933; GB52 (old national standard) has been replaced by GB6170 (new national standard) in the standard book. At present, GB30 (old national standard) has been replaced by GB5783 (new national standard) in the standard book. The metric thread is in MM (mm) and its cusp angle is 60 degrees. In addition, to express American screws, UNC and UNF are usually added after the English screws, so as to distinguish between American coarse teeth and American fine teeth. His concrete meaning is to indicate that the nominal diameter of the screw is 16mm, the pitch is 2mm, and the length is 60mm. Another example: 1/420X3/4 means the inch thread. His specific meaning is that the nominal diameter of the screw is 1. / 4 inches (one inch = 25. For example, M16-2X60 is the metric thread. Due to the different units of measurement, leading to a variety of thread representation is not the same. US Thread thread angle is 60 degrees, The inch thread has a cusp angle of 55 degrees and American threads and inch threads are in inches (4mm), 20 teeth in one inch and 3/4 inch in length. In addition to some basic dimensions such as head-to-edge, head thickness, etc., the above criteria are mainly the difference in the thread portion. In addition to the metric thread and the American thread, there is also a BSW imperial standard, the thread is also in inches, commonly known as Wyeth's thread. GB, DIN, JIS and other threads are all in MM (mm) units, collectively referred to as metric thread. Another thread like ANSI, ASME, etc. is called American Standard thread in inches. The GB standard is one of many standards in China. There are also industry standards, professional standards, and departmental standards. . Standards are divided into: GB (mandatory standards) and GB/T (recommended standards) and GBn (internal standards). The things we usually see like GB30, GB5783, etc. are all mandatory standards. JIS Japanese Standard (Japanese Standard) BSW British Standard DIN German Standard (German Standard) ASME American Society of Mechanical Engineer Standards. wjw. GB Chinese Standard (GB) ANSI American Standard (America Standard) Standard screw, which is a specification, and each department and department Have their own standards. At present, the standards that we commonly use in our ordinary business are the following: In the usual domestic sales business, the standards that we often meet are GB (GB) and DIN (DE). In 1986, we set a new standard for standard parts, commonly known as the new standard in the business. The main ones used are GB5780, GB5781, GB5782, GB5783, and GB5784. GB5784 is a semi-hexagonal screw with a thin rod. ) GB5781 is a hexagonal head full-teeth screw with accuracy class C grade. GB5780 is hexagonal head coarse screw half screw, its accuracy grade is C grade product, can be replaced by GB5782 (GB5782 is hexagonal head thick rod full tooth screw, its precision waits to grade is A grade and B grade. Can use GB5783 to replace (GB5783 Hexagon head full-screw screws with accuracy class A and B).