Service HotlineThe history of screws was broadcast in 1986. Our country formulated a new standard for standard parts, which is commonly known as the new standard in the business. The most used ones are GB5780, GB5781, GB5782, GB5783, GB5784. GB5780 is a hexagonal head thick shank half-thread screw, its accuracy grade is C-grade product, which can be replaced by GB5782 (GB5782 is a hexagonal head thick shank full-thread screw, and its accuracy grade is grade A and B.) GB5781 is a hexagonal head full-thread screw. Threaded screw, the accuracy grade is C grade product. It can be replaced by GB5783 (GB5783 is a hexagonal head full-tooth screw, and its accuracy grades are A and B). GB5784 is a hexagon screw with thin rod and half teeth.
The Greek mathematician Arkutas once described the principle of screw, screw, screw. In the first century AD, the Mediterranean world had begun to use wood screws, screws, and screws in screw presses that could press olive oil from olives, or make wine from grapes. Before the fifteenth century, metal screws, screws, screws were rarely used as fasteners in Europe. Rybczynski (Rybczynski) proves that hand-held screwdrivers and screwdrivers existed in the Middle Ages (at the latest AD 1580), but it was not until the eighteenth century that threaded fasteners were commercialized and began to be widely used. . Before threaded fasteners were widely used, there were many different ways of tightening. Mostly related to woodworking and forging, and less to machining, concepts such as dowels and pins, wedges, tenon and tenon, dovetails, nails, forge welding, and others are tied with leather or fiber and tied together. Before the mid-nineteenth century, ships were built with cotter pins, pin bolts, or rivets. There were also adhesives, but not as many as they are here today. Metal screws, screws, and screws became commonly used fasteners after the use of machine tools in the 18th century to mass-produce screws, screws, and screws. This technology developed around the 1760s and 1770s, along two separate processes. Approaches, but quickly converged: wood screws, screws, screws (metal screws for wood fixing, screws, screws) are machined with single-purpose, high-yield machines, and low-volume, mold shop style production V-Thread Machine Screws, Screws, Screws, can choose from a variety of different pitches.
According to relevant standards, the performance grades of carbon steel and alloy steel bolts are divided into more than 10 grades such as 3.6, 4.6, 4.8, 5.6, 6.8, 8.8, 9.8, 10.9, 12.9, etc. Among them, the bolts of grade 8.8 and above are made of low-carbon alloy steel or medium Carbon steel and heat treatment (quenching, tempering) are generally called high-strength bolts, and the rest are generally called ordinary bolts. The bolt performance grade label consists of two parts of numbers, which represent the nominal tensile strength value and yield ratio of the bolt material respectively. Stainless steel bolts are divided into A1-50, A1-70, A1-80, A2-50, A2-70, A2-80, A3-50, A3-70, A3-80, A4-50, A4-70, A4-80, A5-50, A5-70, A5-80, C1-50, C1-70, C1-110, C4-50, C4-70, C3-80, F1-45, F1- 60. The first letter and number represent the stainless steel group, and the second and third numbers represent 1/10 of the tensile strength. [2]
The round nut is often used with the round nut with a stop washer. When assembling, insert the inner tongue of the washer into the groove on the shaft, and insert the outer tongue of the washer into the groove of the round nut, and the nut will be locked; loose. Often used as the axial fixation of rolling bearings. Round nut with thread size of M10×1～M200×3. The thread specification D=M16×1.5, the material is 45 steel, the groove or all heat treatment hardness HRC35～45, the marking of the surface oxidation round nut: nut GB/T 812-88 M16×1.5.
The retaining ring is a ring-shaped component fastened on the shaft and the inner hole. Its main function is to prevent other components installed on the shaft and the inner hole from sliding axially on the shaft. It is a fixed standard part.
We have many years of experience in the production and sales of screws, nuts, flat washers, etc. The main products are: thin flat washers, iron eyelet rivets, hexagon socket bolts, hexagon socket machine screws and other products, we can provide you with suitable tightening Firmware Solutions.
