What Is an Expansion Spring?
Expansion screws are generally referred to as metal expansion screws. The expansion screws are fixed by using a wedge-shaped slope to promote expansion to produce frictional grip and achieve a fixing effect. The screw is threaded at one end and tapered at one end. The outer bread is a metal sheet (some are steel pipes), half of the metal cylinder (steel pipe) has several cuts, and they are inserted into the hole made in the wall together. Then lock the nut, the nut pulls the screw outwards, and pulls the taper into the metal cylinder The iron cylinder was expanded, so it was tightly fixed on the wall. It is generally used for fastening fences, awnings, air conditioners and other materials on cement and bricks. However, its fixing is not very reliable. If there is a large vibration in the load, it may loosen, so it is not recommended for ceiling fans.
Expansion screw
- Expansion screws are composed of screws and expansion tubes.
- Swell
- Performance grade 10.9 high-strength expansion bolt, after heat treatment, its material can reach:
- 1. The nominal tensile strength of the expansion bolt material is 1000 MPa;
- 2. The yield ratio of the expansion bolt material is 0.9;
- 3. The nominal yield strength of the expansion bolt material is 1000 × 0.9 = 900MPa;
- The meaning of the performance level of expansion bolts is an international standard. The performance of expansion bolts of the same performance level is the same regardless of the material and the origin. The design can only use the performance level.
- The expansion screw is small in drilling, large in tension, and flat after exposure. If it is not in use, it can be removed at will. The advantage of keeping the wall flat is obvious. It is widely used in various decoration occasions.
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- 1. Depth of perforation: The relevant information introduces the length of the expansion tube, but I found that the depth is not enough in the specific construction, which may be related to the amount of debris in the hole, so you better still be 5 mm deeper than the length of the expansion tube about. As long as you are greater than or equal to the length of the expansion tube, the length of the expansion bolts left in the ground is equal to or less than the length of the expansion tube.
- 2. Of course, the requirements of the expansion bolt for the ground are as hard as possible, which depends on the force of the objects you need to fix. When installed in concrete (C13-15), the strength is five times that in bricks.
- 3. After a M6 / 8/10/12 expansion bolt is correctly installed in the concrete, its least ideal maximum static force is 120/170/320/510 kg.
- Picture description of the new inner teeth type metal expansion screw: the scope of application is mainly used in
- Inner tooth metal expansion bolt
Product features
- Wide applicability, simple construction method, high construction success rate, high tensile design, high-strength expansion and expansion, lock payment and anti-loosening effect, no trouble of disposal, recyclable, high-end design concept.
Expansion screw specifications
- 1. M6X25mm 200PCS (NT);
- Main specifications, aperture and size data
- 2. M6X30mm200PCS (NT);
- 3. M8X35mm100PCS (NT);
- 4. M10X50mm100PCS (NT);
- 5.M12X60mm100PCS (NT)
Application scope of expansion screw
- Currently it is mainly used in foreign high-end construction fields, such as Europe, the United States, the Middle East, Japan and South Korea and other developed countries. It entered the domestic market in 2013. It is widely applicable to concrete-embedded operations. Such as: architectural curtain wall, interior decoration, air conditioning, lighting, advertising sign, TV wall hanging, sanitary (kitchenware) water and electricity, monitor and other related industries and fields.
Advantages of expansion screws
- 1. Wide applicability. As long as the size of the male thread matches, it is suitable for any
- Construction of inner teeth type metal expansion screws (2 photos)
Tensile strength of expansion screw
- Tensile strength concrete 25N / mm2 Compared with tensile strength 800kg, hole diameter 10.5mm, drilling depth 40mm. Static vertical load 800 hours / test 500kg displacement 1 mm. The commercially available product (M8) has a tensile force 600kg, a hole diameter of 10.5mm, and a drilling depth of 45mm. Static vertical load 800 hours / test 400kg, displacement 1 mm. However, because currently commercially available products must control the drilling depth or require special tools to be used, poor control of expansion will not affect the tensile strength and even cause the product to fall out. The new type of internal screw length controls the expansion of the female component, which can be completely expanded without causing the female component to fall out.
Expansion screw detection
- Testing method (universal material testing machine): Take 3 ~ 5PCS for concrete block construction test before production, and pull test through universal material machine. The test results can be in batch production after the tensile data meet the formulated tensile data After production, 5 to 10 PCS must be taken. After the relevant third-party inspection agency has obtained the relevant inspection data, the relevant inspection data is obtained. The average data of the two or more.