What is the tolerance range of precision screws?
What is the tolerance range of precision screws?
At present, the standard parts on the market mainly include carbon steel, stainless steel and copper. A carbon steel. We distinguish low carbon steel, medium carbon steel and high carbon steel and alloy steel by the content of carbon in carbon steel material. 1 Low carbon steel C%≤0.25% is usually called A3 steel in China. Foreign countries are basically called 1008, 1015, 1018, 1022, etc. Mainly used for grade 4.8 bolts, grade 4 nuts, small screws and other products without hardness requirements. (Note: 1022 material is mainly used for drill tail screws.) 2 Medium carbon steel 0.25% 3 High carbon steel C%>0.45%. 4 Alloy steel is basically not used in the market: alloying elements are added to ordinary carbon steel to increase some special properties of steel: such as 35, 40 chromium molybdenum, SCM435, 10B38. Fangsheng screws mainly use SCM435 chromium molybdenum alloy steel, the main components are C, Si, Mn, P, S, Cr, Mo. Two stainless steel. Performance grade: 45, 50, 60, 70, 80 1 Mainly divided into austenite (18% Cr, 8% Ni) with good heat resistance, good corrosion resistance and good weldability. A1, A2, A4 2 Martensite, 13%Cr have poor corrosion resistance, high strength and good wear resistance. C1, C2, C4 ferritic stainless steels. 18%Cr has better upsetting and corrosion resistance than martensite. The imported materials on the market are mainly Japan. According to the level, it is mainly divided into SUS302, SUS304 and SUS316. Three coppers. Commonly used materials are brass...zinc-copper alloys. The market mainly uses H62, H65, H68 copper as standard parts.
A nut provided by Yueluo. The nut is in the shape of a sleeve and has a threaded section inside. An annular groove is set on the inner wall of one end of the threaded section. The notch of the groove points to the hole core. The hole diameter at the groove notch at the front end is larger than the nominal size of the thread segment or the hole diameter at the groove notch at the rear end in the screwing direction is smaller than the nominal size of the thread segment.
hand screw is a screw with a plastic head, and the user fixes the hand screw by turning the plastic head by hand. At present, a hand-tight screw is disclosed in the market publication number CN202203253U, which includes a plastic head and a screw rod, the plastic head and the screw rod are connected together, and the height of the plastic head is higher than that of an ordinary screw, and the height is 6 cm. The screw of the hand screw is fixed in the plastic head by glue. After a period of use, the aging of the glue leads to the loosening of the screw and the plastic head. When the plastic head is stressed, the screw rod comes out of the plastic head, which affects the normal use of the hand screw.
Swimming self-locking nut GJB 125.1～125.6-86 The double-ear sealing swimming self-locking nut is composed of four parts: sealing cover, self-locking nut, pressure ring and sealing ring. It has compact structure and reliable sealing, and is suitable for products whose working pressure is not more than 2atm, working medium is gasoline, kerosene, water or air, and the operating temperature is -50～100℃. However, it has certain difficulties in the manufacturing process and air tightness test.
The above content is uploaded by Yueluo or the Internet. If there is any copyright issue, please contact [email protected].
