What is the tolerance range of precision screws?
What is the tolerance range of precision screws?
The t-bolt can be directly put into the groove of the aluminum profile. It can be automatically positioned and locked during the installation process. It is often used in conjunction with the flange nut. profiles to choose from. T-bolts are movable anchor bolts. The existing t-bolt is easy to rotate and swing in the slot during use, which brings some inconvenience to the use of the t-bolt.
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.
The lifting ring screw should be made of 20 or 25 steel (GB699). The lifting ring screw must be forged as a whole. The forgings should be normalized and the oxide scale should be removed. The grain size of the finished product should not be lower than grade 5 (YB27-77). There must be over-burning, crack defects.
Basic parameter broadcast name 1. Machine screw 2. Self-tapping screw 3. Drilling screw 4. Wallboard screw 5. Fiberboard screw 6. Wood screw 7. Hexagon wood screw 8. Non-prolapse screw 9. Combination screw 10. Micro screw 11 . Furniture screws 12. Electronic screws 13. Chain screw head type: 1. Hexagon head (hexagon head) 2. Hexagon head with flange (hexagon head with flange) 3. Square head (square head) 4. T-shaped head T head (hammer head 5. mushroom head (truss head) 6. cylindrical head (cheese head) 7. round head (round head) 8. pan head (pan head) 9. countersunk head (flat head) 10 .Half countersunk head raised countersunk head ( Groove type: 1. Flat 2. Inner triangle 3. Inner corner square 4. Cross 5. Rice shape 6. Flower shape 7. Plum blossom 8. Flower shape 9. Special shape 10. Inner hexagon
The above content is uploaded by Yueluo or the Internet. If there is any copyright issue, please contact [email protected].
