What is the tolerance range of precision screws?
What is the tolerance range of precision screws?
Commonly used screw materials in my country are No. 45 steel, 40Cr, ammoniated steel, 38CrMOAl, superalloy, etc. 1) No. 45 steel is cheap and has good processing performance, but poor wear resistance and corrosion resistance. Heat treatment: quenched and tempered HB220-270, high-frequency quenched HRC45--48. 2) The performance of 40Cr is better than that of No. 45 steel, but it is often plated with a layer of chromium to improve its corrosion resistance and wear resistance. However, the requirements for the chrome plating layer are relatively high. If the plating layer is too thin, it is easy to wear, and if it is too thick, it is easy to peel off. After peeling off, it will accelerate the corrosion, and it has been rarely used. Heat treatment: quenched and tempered HB220—270, hard chrome plated HRC>553) nitrided steel, 38CrMoAl have excellent comprehensive properties and are widely used. Generally, the nitride layer reaches 0.4-0.6 mm. However, this material has low resistance to hydrogen chloride corrosion and is relatively expensive. 4) The superalloy material is superior to other materials. This material does not need coating, and is mainly used for the raw halogen-free screw of injection molding machine. The material has high oxidation resistance and corrosion resistance.
In view of the deficiencies of the prior art, a simple structure is provided, which can ensure that the nut body and the washer are assembled together during the production of the wheel nut, and will not be separated from each other in any occasion, so as to ensure the reliability of the assembly, and the nut will no longer appear. The wheel nut assembly that needs to be reassembled after use or placement saves time and effectively improves the convenience of the wheel nut when it is used or placed
The flange nut and the general hexagon nut are basically the same in size and thread specification, but compared with the hexagon nut, the gasket and the nut are integrated, and there are anti-skid tooth patterns on the bottom, which increases the nut and the workpiece. Compared with the combination of ordinary nut and washer, it is stronger and has greater tensile force. In some equipment with large vibration amplitude, due to the action of huge vibration force, the flange nut is prone to loosening, which often occurs. If the flange nut falls off the equipment or even damages, the staff also needs to install the flange nut repeatedly, which increases the labor intensity and brings great inconvenience to the use. Now a split type tightening nut is proposed.
The rubber ring and the metal ring are integrally bonded and vulcanized. It is a sealing ring used to seal the thread and flange connection. The ring includes a metal ring and a rubber gasket. The metal ring is rust-proof, and the rubber ring is generally made of oil-resistant nitrile rubber or fluororubber. Combination pads are available in metric and inch sizes, and the standard JB982-77 specifies the combination of metal pads and rubber. Combination sealing washer is used for threaded pipe joints and screw plug sealing. It is generally used with ferrule type pipe joints to block oil ports. It is mainly used for end face static sealing of threaded joints of hydraulic valve pipe joints. It is suitable for British and American standards. Inch thread and end face static seal at French and German standard metric thread connections, etc. The combined sealing gasket can be divided into A type and B type according to the structure; it can be divided into full package and half package according to the difference of rubber.
The above content is uploaded by Yueluo or the Internet. If there is any copyright issue, please contact [email protected].
