What is the tolerance range of precision screws?
What is the tolerance range of precision screws?
The gasket refers to the part between the connected part and the nut, which is generally a flat metal ring, which is used to protect the surface of the connected part from scratches by the nut and disperse the pressure of the nut on the connected part.
In the prior art, the earliest rivets were small pegs made of wood or bone, and the earliest metal deformations were probably the ancestors of the rivets we know today. Without a doubt, they are the oldest known method of metal joining, dating back as far as the earliest use of malleable metals, for example: the Bronze Age Egyptians used rivets to attach six wooden sectors to the outer lines of a slotted wheel Riveted and fastened together. After the Greeks successfully cast large statues in bronze, they then used rivets to rive the parts together. With the progress of the times, there are more and more types of rivets, but traditional rivets have connection strength. Insufficient problem, so a new rivet is needed to solve the above problem.
flat washer is also called a flat washer. It is mainly stamped out of an iron plate. The shape is generally a flat washer with a hole in the middle. The size of this hole is generally determined according to customer requirements. There are 9 standards for flat washers in my country. From 2000 to 2002, GB/T97.3-2000, GB/T5286-2001, GB/T95-2002, GB/T96.1-2002, GB/T96.2 were approved and released respectively. -2002, GB/T97.1-2002, GB/T97.2-2002, GB/T97.4-2002 and GB/T5287-2002 Standard for flat washers. According to the performance grade of the flat washer, the author recommends the use of materials: ST12, ST13, Q235, Q215, Q195, etc. can be selected for the 100HV grade, and the surface hardness can reach about 110HV; 08F, 08Al, 10, 10F, etc. can be selected for the 140HV grade etc., the surface hardness can reach about 140HV; for 200HV and 300HV grades, 45, 50, 60, 70 or 65Mn steel should be selected, which can be quenched and tempered by heat treatment to meet the technical requirements of 200~300HV and 300~400HV. Because according to the standard, flat washers of 100HV and 140HV grades can be manufactured from mild steel. Most enterprises use Baosteel materials when selecting materials, which is convenient for cold stamping. The following is a brief description of Baosteel's standards. Compared with the BZJ407-1999 standard, there are major changes in Continuous Cold Rolled Low-Carbon Steel Plates and Strips and the enterprise standard: (1) The grades have been revised and integrated, and the grades have been changed from 8 commonly used to 5. St12 is changed to DC01; ST13 is changed to DC03; St14, St15 is changed to DC04; BSC2 is changed to DC05; St16, St14-T, BSC3 is changed to DC06. (2) The surface quality level is changed from two to three: the higher-level finishing surface (FB), the surface is allowed to have a small amount of defects that do not affect the formability and coating and plating adhesion, such as slight scratches, indentations, Pock, roll printing and oxidation color, etc. Premium Finished Surface (FC) products have no visible defects on the better of the two sides and must meet at least FB requirements on the other side. The super-advanced finishing (FD) product must not have any defects on the better side of the two sides, that is, it cannot affect the appearance quality after painting or the appearance quality after electroplating, and the other side must at least meet the requirements of FB. (3) The surface structure is modified from four to two, and the control value of surface roughness is increased. The average roughness Ra when the surface structure is pitted (D) is 0.6 μm. (4) The provisions on Si and residual elements in the chemical composition of the five grades have been cancelled, and the contents of elements such as C, S, and Alt have been revised.
The purpose of Guangdong Yueluo Hardware Industry Co., Ltd. is to provide an improved lock nut to solve the problem that the production technology of the prior art products is too complicated. For realizing the above-mentioned purpose, Guangdong Yueluo Hardware Industry Co., Ltd. adopts following technical scheme—a kind of locking nut, which comprises that the bottom of the nut is a circle, the middle part is a hexagon, and the top is a circle, and there are bolts in the center.
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