The expansion screw is composed of a screw and an expansion pipe, the tail of the screw is conical, and the inner diameter of the cone is larger than that of the expansion pipe. When the nut is tightened, the screw moves outward, and the conical part moves through the axial movement of the thread, so that a great positive pressure is formed on the outer peripheral surface of the expansion pipe, and the angle of the cone is very small, so that friction self-locking is formed among the wall, the expansion pipe and the cone, and the fixing effect is achieved.After screening and investigation Hub bolt It is likely to become a new force driving economic development. https://www.chinatianlong.com/
The spring washer on the expansion screw is a standard part. Because its openings are staggered and elastic, it is called a spring washer. The function of the spring washer is to use the sharp corner of the staggered mouth to pierce the nut and the flat washer to prevent the nut from loosening.
The flat pad is also a standard part, and its function is to evenly distribute the pressure of the nut on the connected parts.
Expansion screw specifications:
The grades of expansion bolts are: 45, 50, 60, 70, 80,
The materials of expansion screws are mainly divided into austenite A1, A2 and A4.
Martensite and ferrite C1, C2, C4,
Its representation method is, for example, A2-70,
”-“indicates bolt material and strength grade before and after, and the following is a complete specification table of expansion bolts.
For 45 # steel, alloy steels with high mechanical properties, such as 15Cr, 20Cr, 40Cr, 15MnVB and 30CrMrSi, can be selected for important or special-purpose threaded joints.
Choose different expansion screws according to the actual situation of the wall. Generally, there are the following 6〜60, 6〜80, 6〜120 and 6〜150.
6〜60: the total length is 60 mm, the sleeve is 45 mm long, the diameter is 8 mm, the wall thickness is 0.7 mm, and the surface is coated with colored zinc; The screw is 60 mm long, 6 mm in diameter, 35 mm in threaded part and 8mm in bottom hammer, and the surface is coated with colored zinc; The nut is octagonal with an outer diameter of 10 mm and a thickness of 5 mm, and the surface is plated with white zinc; The outer diameter of the gasket is 13 mm, the thickness is 1mm, the inner diameter is 6 mm, and the surface is plated with white zinc; The elastic sheet is a ring with an out diameter of 9 mm, an inner diameter of 6 mm and a thickness of 1.6 mm.
6〜80: the total length is 80 mm, the sleeve is 65 mm long, the diameter is 8mm, the wall thickness is 0.7 mm, and the surface is coated with colored zinc; Screw length, nut, gasket and elastic sheet are the same as above.
6〜120: the total length is 120mm, the sleeve is 105mm long, the diameter is 8mm, the wall thickness is 0.7 mm, and the surface is coated with colored zinc; Screw length, nut, gasket and elastic sheet are the same as above.
6〜150: the total length is 150mm, the sleeve is 135mm long, the diameter is 8mm, the wall thickness is 0.7 mm, and the surface is coated with colored zinc; Screw length, nut, gasket and elastic sheet are the same as above.