Fastener product screw details

The unit of metric thread is MM (mm), and its cusp angle is 60 degrees. Both American and Imperial threads are measured in inches. The apex angle of the American thread is also 60 degrees, while the apex angle of the British thread is 55 degrees. Due to the different units of measurement, the representations of various threads are also different. For example, M16-2X60 means metric thread. His specific meaning is that the nominal diameter of the screw is 16MM, the pitch is 2MM, and the length is 60MM. For example: 1/4-20X3/4 is an inch thread. His specific meaning is that the nominal diameter of the screw is 1/4 inch (one Inch=25.4MM), there are 20 teeth in one inch, and the length is 3/4 inch. In addition, in order to represent American screws, UNC and UNF are usually added after imperial screws to distinguish American coarse teeth or American fine teeth. In the usual domestic sales business, the most commonly encountered standards are GB (National Standard) and DIN (German Standard).
For non-party products, the main standards are: GB30; GB5783; GB5782; GB 52; GB6170; GB 818; GB 819; GB 845; GB 846; GB 70; ) has been replaced by GB5783 (new national standard). GB52 (old national standard) has been replaced by GB6170 (new national standard) in the standard book. In 1986, the state formulated a new standard for standard parts, commonly known as the new standard. The most commonly used are GB5780, GB5781, GB5782, GB5783, GB5784. GB5780 is a hexagon head thick shank half tooth screw with a precision grade of C, which can replace GB5782 (GB5782 is a hexagon head thick shank full tooth screw with a precision of A and B grades.) GB5781 is a hexagon head full tooth screw with an accuracy grade of C class. It can be replaced by GB5783 (GB5783 is a hexagonal head full-tooth screw, and the accuracy grades are grades A and B). GB5784 is a hexagonal screw with a thin rod and a half thread. The difference between the new standard and the old standard lies in the width of the reverse side of the M8, M10, M12, M14, and M22 series products. In addition to the new products of the M22 series, the heads of the new standard products M8, M10, M12, and M14 are 1 mm smaller than the old models. They are 13, 16, 18, 21MM respectively. M22 series new product, the new standard is 2MM larger than the old one. Special attention should be paid. For the thickness of the head, the new standard is slightly different from the old standard, and it can be used universally if the requirements are not very strict. The difference between the new standard and the German standard is that the product specifications of M10, M12, M14, and M22 are different in width across sides. The head-to-side new standard of M10, M12 and M14 is 1MM smaller than the German standard. M22's new head edge width is 2mm larger than the German standard. Others can be used universally.
For hex nuts, commonly used standards are: GB52, GB6170, GB6172 and DIN934, the main difference between them is: GB6170 is thicker than GB52, GB6172 and DIN934, commonly known as thick nuts. The other is the difference of opposites. In the M8 nut series, the opposite sides of DIN934, GB6170, and GB6172 are 13MM smaller than the opposite sides of GB52, which are 14MM smaller. For M10 nuts, the opposite sides of DIN934 and GB52 are 17MM, which are 1MM larger than those of GB6170 and GB6172. For M12 nuts, the opposite sides of DIN934 and GB52 are 19MM, which are 1MM larger than those of GB6170 and GB6172 18MM. The M14 nut is 22MM opposite to DIN934 and GB52, which is 1MM larger than the 21MM opposite to GB6170 and GB6172. The other is an M22 nut. The reverse side of DIN934 and GB52 is 32MM, which is 2MM smaller than the 34MM opposite side of GB6170 and GB6172. (Except for the different thicknesses of GB6170 and GB6172, the opposite widths are exactly the same) The rest of the specifications can be used regardless of the thickness.