What is the tolerance range of precision screws?
What is the tolerance range of precision screws?
For common screw belts, please refer to the Central Taiwan Announcement No. 327442 Screw Belts (2) on February 21, 1998. It includes a main body, and there are multiple grooves on the side of the main body, which are used for locking screw tools to drive the belt. A toggler; and a plurality of nail grooves are arranged on the nail belt so that the screw planting is arranged in an arrangement, and the nail grooves are all provided with through holes, and the through holes extend downward with a ring to form a support portion for the screws; and the It is surrounded and provided with a plurality of cutting grooves, which is beneficial for the screw to be rotated through the nail groove; and it is characterized in that the nail groove is located on the inner wall surface of the surrounding and is provided with a plurality of lobes, and these lobes are implanted in the screw. In the nail groove, the leaflet supports the screw, so that the screws with different outer diameters are fully supported and positioned by the leaflet; and/or the upper part of the leaflet is inclined or curved, so that a depression is formed above the ring to support the screw The arc surface or tapered surface of the neck can make the screw more stable to be supported.
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.
Anti-corrosion technology Stainless steel screws are made of metal, and there are four main methods for metal anti-corrosion, namely the properties of the material itself, the environment of use, the interface between materials and the environment, and the improvement of the metal structure design. If a complete anti-corrosion alloy is used to make stainless steel Screws, unless there is a special need, are not cost-effective in terms of economics, and it is also impractical to completely isolate the appearance of the screw from environmental elements that can cause corrosion. Improving the metal structure design can improve the influence of special circumstances under certain conditions, but the design of most stainless steel screws cannot be fully corrected, and its maintenance effect is not permanent, so this method cannot basically solve the problem, as long as it is on the surface. Top anti-corrosion, that is, surface anti-corrosion treatment is the most widely used method. The anti-corrosion treatment on the surface of stainless steel screws refers to the use of various methods to apply a protective layer on the metal surface. The purpose of avoiding or mitigating corrosion. The protection layer should be able to meet the following requirements: 1. Corrosion resistance, wear resistance, high hardness, 2. The structure is tight, intact, and the pores are small. 3. It has strong separation and good adhesion with the base metal. 4. It is evenly distributed and has a certain thickness. The maintenance layer is usually divided into two types: metal coating and non-metallic coating. Metal coating refers to the use of metal or alloy with strong corrosion resistance to form a maintenance layer on the surface of metal that is easy to corrode. This coating is also called plating. There are quite a few methods and varieties to produce metal coatings, the most common of which is electroplating, followed by molten metal immersion plating (hot dipping) and chemical surface treatment. Non-metallic coating refers to the use of organic polymer materials such as paint and inorganic materials such as ceramics to form a protective layer on the surface of metal equipment or parts. The protective layer can completely isolate the base metal from the environmental medium and prevent the base metal from corrosion due to contact. Corrosion is formed in the medium of stainless steel standard parts.
The rod end of the ceramic production equipment is installed with the rod shaft, and then fixed by the cylindrical pin. At present, it is purely manual installation. It is impossible to ensure that the cylindrical pin is kept horizontal during the installation process, and the installation pressure of the cylindrical pin cannot be sensed. The pressure is too large. Cracks in the rollers, too low pressure, and easy loosening of the metal cap; it is impossible to install three or more cylindrical pins at the same time, and it is difficult to align the cylindrical pins with the pin holes of the cylindrical pins, resulting in low efficiency.
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