Carbon steel galvanized external expansion bolt

roduct description: Expansion bolts are special threaded connections used to fix pipeline supports/hangers/brackets or equipment on walls, floors, and columns. The grades of carbon steel bolts are divided into more than 10 grades, such as 3.6, 4.6, 4.8, 5.6, 6.8, 8.8, 9.8, 10.9, and 12.9.
Material: The grades of expansion bolts are divided into 45, 50, 60, 70, 80;
The materials are mainly divided into austenite A1, A2, A4;
Martensite and ferrite C1, C2, C4;
Its representation method is for example A2-70;
The front and back of "--" respectively indicate bolt material and strength grade.
(1) Bolt material Common materials: Q215, Q235, 25 and 45 steels. For important or special-purpose threaded joints, alloy steels with higher mechanical properties such as 15Cr, 20Cr, 40Cr, 15MnVB, 30CrMrSi, etc. can be used.
(2) Allowable stress The allowable stress of the threaded connection is related to the nature of the load (static and variable load), whether the connection is tightened, whether the pre-tightening force needs to be controlled, and the material and structural dimensions of the threaded connection.

Classification: The grades of stainless steel bolts are divided into 45, 50, 60, 70, and 80. The materials are mainly divided into austenite A1, A2, A4, martensite and ferrite C1, C2, C4, and the expression method is A2-70. , Before and after "--" respectively indicate bolt material and strength grade

Composition: Expansion bolts are composed of countersunk bolts, expansion tubes, flat washers, spring washers and hexagon nuts.

Use: When using, you must first drill holes of the corresponding size in the fixed body with an electric impact drill (hammer), then put the bolts and expansion tubes into the holes, and tighten the nuts to fix the bolts, expansion tubes, and installation parts. The body swells tightly into one body.

After tightening, it will expand. The bolt has a large end. The bolt is covered with a round tube slightly larger than the diameter of the bolt. There are several openings at the end. When the bolt is tightened, the large end of the bolt is brought into the open tube. Make the pipe bigger to achieve the purpose of expansion, and then fix the bolt on the ground or wall to achieve the purpose of rooting.

Principle: The fixing principle of the expansion screw: The fixing of the expansion screw is to use the inclination of the shape to promote the expansion and generate the frictional binding force to achieve the fixing effect. One end of the screw is threaded, and the other end is tapered. There is a steel skin on the outside, and half of the iron skin cylinder has several cuts. Put them together into the holes made in the wall. Then lock the nut and the nut to pull the screw outwards to pull the conical degree into the steel skin cylinder. The steel skin is round. The tube is expanded, so it is tightly fixed to the wall, and is generally used to fasten protective fences, awnings, air conditioners, etc. on cement, bricks and other materials. But its fixing is not very reliable. If the load has a large vibration, it may loosen, so it is not recommended to install ceiling fans. The principle of the expansion bolt is to drive the expansion bolt into the hole on the ground or the wall, and then use a wrench to tighten the nut on the expansion bolt. The bolt goes out, but the outer metal sleeve does not move. The metal sleeve expands so that it fills the entire hole. At this time, the expansion bolt cannot be pulled out.
Installation steps: 1. Choose an alloy drill bit that matches the outer diameter of the inner expansion bolt, and then drill the hole according to the length of the inner expansion bolt. Drill the hole as deep as you need for installation, and then clean the hole. 2. Install the flat washer, spring washer and nut, screw the nut to the bolt and the end to protect the thread, and then insert the inner expansion bolt into the hole. 3. Turn the wrench until the washer and the surface of the fixed object are flush. If there is no special requirement, usually tighten it by hand and then use the wrench for three to five turns.
Matters needing attention: 1. Depth of drilling: The depth of the specific construction is preferably about 5 mm deeper than the length of the expansion pipe. As long as it is greater than or equal to the length of the expansion pipe, the length of the inner expansion bolt left in the ground is equal to or less than the length of the expansion pipe.
2. The requirement of the inner expansion bolt on the ground is of course the harder the better, it also depends on the force of the object you need to fix. Installed in concrete (C13-15), the force strength is five times that of bricks.
3. After a M6/8/10/12 inner expansion bolt is correctly installed in the concrete, its ideal maximum static force is 120/170/320/510 kg respectively. The installation method of the inner expansion bolt is not very difficult, the specific operation is as follows; first select an alloy drill with the same diameter as the expansion screw expansion ring (tube), install it on the electric drill and then perform wall drilling. The depth of the hole is best The length of the bolts is the same, and then the expansion screw kit is lowered into the hole together, remember; do not screw off the screw cap, to prevent the bolt from falling into the hole when the hole is drilled deeper, and it is not easy to take it out. Then tighten the screw cap 2-3 buckles, and then unscrew the screw cap after feeling that the inner expansion bolt is relatively tight and not loose.