Service HotlineThe meaning of bolt performance grade is an international standard. Bolts of the same performance grade, regardless of the difference in material and origin, have the same performance, and only the performance grade can be selected in the design. Strength grade The so-called 8.8 and 10.9 grades refer to the shear stress grades of bolts of 0.88GPa and 1.09GPa 8.8 Nominal tensile strength 800N/MM2 Nominal yield strength 640N/MM2 General bolts use XY to indicate the strength, X *100=tensile strength of this bolt, X*100*(Y/10)=yield strength of this bolt (because according to the regulations: yield strength/tensile strength=Y/10, that is, 0.Y is the yield strength ratio ) If the grade is 4.8, the tensile strength of this bolt is: 400MPa; the yield strength is: 400*8/10=320MPa. Another: stainless steel bolts are usually marked as A4-70, A2-70, and the meaning is otherwise explained Measurement: There are two main units of length measurement in the world today, one is the metric system, and the measurement unit is meters (m) and centimeters (cm). ), millimeter (mm), etc., are used more in Europe, my country and Japan and other Southeast Asian regions, the other is the British system, and the unit of measurement is mainly inches (inch), which is used more in the United States, Britain and other European and American countries. 1. Metric measurement: (decimal system) 1m2 =100 cm2=10000 mm2, imperial measurement: (8 decimal system) 1 inch = 8 inches 1 inch = 25.4 mm 3/8¢¢×25.4 =9.523, 1/4 ¢¢ The following products are indicated by their number, such as: 4#, 5#, 6#, 7#, 8#, 10#, 12#
As one of the screws, self-tapping screws can directly drill holes on the plate to be fixed by themselves and lock them together with the plate to be fixed. They are easy to use and have a good fixing effect, so they are widely used. However, in the prior art, when the screw is perforated on the plate to be fixed, it is prone to skew, which affects the fixing effect and also reduces the aesthetics. To sum up, how to overcome the above-mentioned defects of the screw fixing method in the prior art is a technical problem to be solved urgently by those skilled in the art.
Common types of common screws All kinds of common screws (20 pieces) a. Slotted: a word ( Minus ) b. Phillips: cross ( Plus ) c. Phil-Slot: a word / cross d. Hex Socket: hexagon socket e. One Way: One-way (can only be locked in, not out) A-4: Head Code/ head shape. a. Flat: Flat head (after locking, the top is flush with the work piece) b. Oval: salad head, O head, countersunk head screw unit of measure screw unit of measurec. Round: round headd. Pan: round flat heade. Truss: large round flat headf. Hex: hexagon head. A-5: Finish Code/Appearance treatment. Metric Self-tapping screw: Mark Tapping Type directly behind the product name. Ex: M3 x 6 –PPB, Tapping Type: M3 self-tapping screw, 6mm long, cross, round flat head, black plated. Generally, it is determined by product type or mark. For Sheet Metal or plastic parts. *Pitch = Threads per inch
Installation method broadcast 1. One-time burying method: When pouring concrete, bury the anchor bolts. When the high tower is controlled by overturning, the anchor bolt should be buried once. 2. Reserved hole method: The equipment is in place, the holes are cleaned, the anchor bolts are placed in the holes, the equipment is positioned and aligned, and then poured with non-shrinkage fine stone concrete that is one level higher than the original foundation, and compacted and compacted. . The distance from the center of the anchor bolt once buried to the edge of the foundation should not be less than 2d (d is the diameter of the anchor bolt), and should not be less than 15mm (d≤20, it should not be less than 10mm), not less than half the width of the anchor plate Add 50mm, when the above requirements cannot be met, appropriate measures should be taken to strengthen it. The diameter of the anchor bolts used for the structure should not be less than 20mm. When subjected to earthquake action, double nuts should be used for fixing, or other measures to effectively prevent loosening should be adopted, but the anchorage length of anchor bolts should be increased by 5d compared with the anchorage length of non-seismic action. Installation planning of anchor bolts Treatment of anchor bolts loose in the foundation When the anchor bolts are tightened, the bolts may be pulled out. At this time, the bolts should be adjusted to their original positions, and the foundation around the bolts should be shoveled out enough. , and then weld two U-shaped steel bars vertically and horizontally on the bolts, and finally clean the pit with water and grouting, and then tighten the live anchor bolts after the concrete has solidified to the design strength. The treatment method of the live anchor bolt deviation is roughly the same as the dead ground. The method for the anchor bolts is the same, except that the anchor bolts can be pulled out for processing. If the bolt is too long, a section of the thread can be cut off on the machine tool; if the bolt is too short, it can be extended by hot forging; if the position is inconsistent, it can be corrected by bending. Application industry: suitable for various equipment fixing, steel structure foundation embedded parts, street lights, traffic signs, pump, boiler installation, heavy equipment embedded fixing, etc.
With the development of science and technology, the advancement of technology, the rapid change of automotive products, also put forward higher requirements for fastener products, and automotive fastener-related products, especially in the process of assembling auto parts, in order to effectively improve the bolts The fastening strength is mostly made of combined gaskets (flat gaskets, cone gaskets) and riveted nuts to meet the assembly requirements.
We have many years of experience in the production and sales of screws, nuts, flat washers, etc. The main products are: hand-tightened ingot bolts, T-shaped aluminum groove pressure plate screws, black galvanized cup head socket head cap bolts, Torx screws and other products, we can Provide you with the right fastener solution for you.
