Standard is standard, each country and departments have their own standards. Currently, we are usually the most commonly used business standards are the following:
GB? Chinese National Standard (GB) ANSI? American National Standards Institute (ANSI)
DIN? German national standard (DIN) ASME? United States Machinery Engineers standards
JIS? Japan National Standards (JIS) BSW? British national standards
GB? National standard is a country of many standards, in addition to industry standards, professional standards and departmental standards. National standard is divided: GB (mandatory standards) and GB / T (a recommended standard) and GBn (internal standard) and so on. We normally see as GB30, GB5783, etc. are mandatory standards.
Several standard in addition to the above basic dimensions such as head-to-edge, the thickness of the different head outside, the most important part is the different threads. GB, DIN, JIS, etc. there is a thread MM (mm) as a unit, collectively known as the metric thread. The other as ANSI, ASME and other units of inch thread is known as the American standard thread. In addition to metric thread outside the U.S. system, there is a thread BSW? British standards, the thread is to inch as a unit, commonly known as Wyeth thread.
Metric thread by MM (mm) as a unit, its teeth sharp angle of 60 degrees. American and British screw thread as the units are in inches. American thread tooth cusp is 60 degrees, while the British thread 55 degree cusp teeth. Because the different units of measurement, leading to a variety of threads that a different approach. Such as the M16-2X60 is expressed in metric threads. He specifically means that the screw the nominal diameter of 16MM, tooth distance 2MM, length of 60MM, and if: 1 / 4? 20X3 / 4 that is British in the thread, he specifically means that the screw nominal diameter 1 / 4 inch (1 inch = 25.4MM), one inch, 20 teeth, the length is 3 / 4 inches. In addition to that, then screw the U.S. system will normally be added after that inch screws UNC and UNF, the U.S. system in order to distinguish coarse or fine tooth US-made.
Domestic operations in peacetime, we most often encounter a standard GB (GB) and DIN (German standard).
Students in non-aromatic products, the main access to the following standards: GB30; GB5783; GB5782; GB52; GB6170; GB818; GB819; GB845; GB846; GB70; DIN912; DIN933; DIN931 and so on. Currently GB30 (Old GB) in the standard book has been GB5783 (the new national standard) are replaced. GB52 (Old GB) in the standard book have been GB6170 (the new national standard) are replaced.
In 1986, the standard parts of our country to develop a new standard in the business commonly known as the new standard, the most used mainly GB5780, GB5781, GB5782, GB5783, GB5784. GB5780 hexagonal head coarse thread screw rod and a half, its accuracy rating for a C-class products that can be used in place of GB5782 (GB5782 hexagonal head coarse thread screw rod all, until the level of accuracy for the A-and B-class.) GB5781 hexagonal head for the whole screw, precision grade is C-class product. Can be used in place of GB5783 (GB5783 hexagonal head screws the whole tooth, its accuracy rating for A-and B-class). GB5784 for the rod and a half teeth hexagonal screws.
New standard with the old target difference is: M8, M10, M12, M14, M22 series of products, the width of the edge differ. In addition to M22 series of new products, new standard products M8, M10, M12, M14 on the side of the head on the side of the subject than the old smaller 1MM. Were 13,16,18,21 MM, and M22 series of new products, new object on the edge than the old standard but to a large 2MM, should pay particular attention. The thickness of the heads, the new standard and the slight difference between the old standard, the requirements are not very stringent conditions may be common.
New standards and moral difference between the subject : M10, M12, M14, M22 product specifications, in some variations in the width of the edge. M10, M12, M14 head on the edge of new standard is smaller than the German standard 1MM. The M22′s new products, and its head on the side of the subject on the edge than the width of Germany and larger 2MM, others are accepted.
The hexagonal nut, common standards: GB52, GB6170, GB6172 and DIN934, the main differences between them are: GB6170 thickness than the GB52, GB6172 and DIN934 to the thick, commonly known as the thickness of the nut. The other is on the edge of the difference, M8 nut series DIN934, GB6170, GB6172′s on the edge are 13MM 14MM edge than the GB52′s smaller 1MM, M10 nuts, DIN934 and GB52 of the right side of the 17MM, compared GB6170 and GB6172 to the right side of larger 1MM, M12 nut , DIN934, GB52 for the 19MM on the opposite side than the right side of GB6170 and GB6172 18MM larger 1MM. For the M14 nuts, DIN934, GB52 for the 22MM on the opposite side than the right side of GB6170 and GB6172 21MM larger 1MM. The other is the M22 nuts, DIN934, GB52′s on the side of the 32MM, compared with GB6170, GB6172′s on the smaller side 34MM 2MM. (GB6170 and GB6172 not the same as in addition to its thickness, the same width on the side) does not consider the thickness of the remaining specifications in the case, can be common .
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