How to hit the expansion screw?
1. First measure the position to be drilled, and mark the position to be drilled with a pencil;
How to hit the expansion screw? Installation precautions, working principle, scope of use, etc.
2, according to the size of the expansion screw you use, choose a suitable drill (the diameter of the drill is equivalent to the diameter of the expansion pipe), and punch holes in the wall with a hand electric drill (the depth of the hole is greater than the length of the expansion pipe, so as to avoid the expansion pipe being completely plugged into the wall);
How to hit the expansion screw? Installation precautions, working principle, scope of use, etc.
3. Clean the sand in the hole with a small stick to avoid sand blocking and inconvenient installation;
4. Completely smash the expansion tube into the hole with a hammer;
How to hit the expansion screw? Installation precautions, working principle, scope of use, etc.
5. Pass the screw through the mounting hole of the fixed object, screw it into the expansion tube with a screwdriver and tighten it.
How to hit the expansion screw? Installation precautions, working principle, scope of use, etc.
Precautions for installing expansion screws
1, drilling depth: the relevant information introduces the length of the expansion pipe, but I found that this depth is not enough in the specific construction, which may be related to the amount of debris left in the hole, so you'd better be about 5 mm deeper than the length of the expansion pipe. As long as you are greater than or equal to the length of the expansion pipe, the length of the expansion bolt left in the ground is equal to or less than the length of the expansion pipe;
2. The requirement of the expansion bolt on the ground is of course that the harder the better, which also depends on the stress of the object you need to fix. The stress intensity of concrete (C 13- 15) is five times that of brick.
3. After an M6/8/ 10/ 12 expansion bolt is correctly installed in concrete, its most unsatisfactory maximum static stress is120/170/320/510 kg respectively.
Working principle of expansion screw
1. The expansion screw consists of a screw and an expansion tube. 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 pipe wall, the expansion pipe and the cone, and the fixing effect is achieved;
2. The spring washer on the expansion screw is a standard part, because its openings are staggered and elastic, so it is called spring washer. The function of the spring washer is to pierce the nut and the flat washer with the sharp corner of the staggered mouth to prevent the nut from loosening;
3. The flat pad is also a standard part, and its function is to evenly distribute the pressure of the nut on the connected parts.
Scope of application of expansion screw
Expansion screws are widely used in various decoration occasions because of their small drilling, large tension and flat exposure after use. If it is not used, it can be removed at will to keep the wall flat.
1, fasten air conditioner, water heater, range hood, etc. ;
2. Fix frameless balcony window users, anti-theft doors and windows, kitchen and bathroom components, etc.
3, ceiling screw fixation (combined with casing and cone cap).
Classification of expansion screws
A performance grade of 4.6 expansion bolt, its meaning is:
1, and the nominal tensile strength of the expansion bolt material reaches 400MPa.
2. The yield ratio of the expansion bolt material is 0.6;
3. The nominal yield strength of the expansion bolt material reaches 400×0.6 = 240 MPa；;
The meaning of performance grade of expansion bolt is an international standard. The performance of expansion bolts with the same performance grade is the same regardless of their material and origin. Only performance levels can be selected in the design.
Second, the high-strength expansion bolt with performance grade of 10.9, after heat treatment, its material can reach:
1, and the nominal tensile strength of the expansion bolt material reaches1000 MPa;
2. The yield ratio of the expansion bolt material is 0.9;
3. The nominal yield strength of the expansion bolt material reaches1000× 0.9 = 900 MPa;
The meaning of performance grade of expansion bolt is an international standard. The performance of expansion bolts with the same performance grade is the same regardless of their material and origin. Only performance levels can be selected in the design.
Advantages of expansion screw
1, with wide applicability. As long as the male thread size is consistent, it is suitable for any type of anchor head;
2. Selection of construction methods. Fixed-point presetting can be used as required, and drilling (loading) can also be carried out once, and its function and effect are completely consistent;
3. The construction success rate is high. There is no trouble of hole attachment depth and borehole inclination, and the construction achievement rate is100%;
4. High-pitched design. Design of special hook for full tooth taper expansion:
5. Locking and locking effect. Special design of full-tooth taper expansion, using reverse thrust effect to lock the workpiece urgently;
6. Improve design thinking. Short and pithy, it is suitable for matching all commercially available screws, DIY and the most desirable building accessories for fortifications;
7. Ensure that the anchor bolt expands. Metal plate pressed products, patented full-tooth taper expansion design, strong grasping ability, no idling, no need for professional construction skills;
8. Disposal is not troublesome. As long as the anchor bolt workpiece is pulled out and the plane is repaired with filler, there is no trouble of disassembly and no danger of bump.
Tensile strength of expansion screw
Compared with 25N/mm2, the tensile strength of concrete is ≧800kg, the aperture 10.5mm, the drilling depth is 40mm, the static vertical load is 800h/test ≦500kg displacement ≦1mm; The commercial product (M8) has a tensile strength of ≧600kg, a hole diameter of 10.5mm, a drilling depth of 45mm, a static vertical load of ≦400kg, and a displacement of ≦1mm. However, at present, the commercially available products can only be used if the drilling depth is controlled or special tools are needed, and incomplete expansion will affect the tensile strength. However, the length of the new internal thread controls the expansion of the female part, and the female part can fully expand without falling out.
How to detect expansion screws
Before production, take 3 ~ 5pcs for concrete block construction test, and after the universal material machine drawing test, the test results meet the established tensile data, mass production can be carried out. After mass production, take 5 ~ 10pcs as the object, and then do relevant test data after inspection by a third-party testing organization, and the average data of the above two.
Specification and model of expansion screw
1, M6X25mm 200PCS (NT);
2. M6X30mm200PCS (NT);
3. M8X35mm 100PCS (NTD);
4. M 10X50mm 100PCS (NTD);
5. m 12x 60mm 100 pieces (NTD).
The above is the driving method, installation precautions, working principle, scope of application, classification, advantages, compression resistance, testing methods and specifications of expansion screws introduced by Ji Xian. com。 Its fixation is not very reliable. If the load vibrates greatly, it may loosen, so it is not recommended to install ceiling fans.