I. What is an internal expansion bolt?
The internal expansion bolt aims to add a new internal expansion fastener. It comprises a bolt, a washer, a sleeve, an expansion pipe and a nut, wherein the bolt is a flat head and the nut is a cone head, and the washer, the sleeve and the expansion pipe are sequentially placed between the bolt and the nut. The utility model adopts the sleeve structure, which digests the trend of "connecting rod turning" and is easy to fasten the positioning point. The cone mother has a gentle slope, stable unfolding, difficult node loosening, large unfolding working area and reliable working condition. The bolt head is close to the wall, and there is no room for retraction, so the lock will not unlock. When tightening, the bolt does not shift, so there is no worry about the joint head. Without cutting, the coating will not be destroyed. Screws can be screwed out and anchor points can be easily eliminated. The appearance is beautiful and consistent.
Second, the internal expansion bolt installation steps
1. Select the alloy drill bit that matches the external diameter specification of the internal expansion bolt, then drill the hole according to the length of the internal expansion bolt until the hole is deep enough for you to install, and then clean the hole.
2. Install the flat pad, spring pad and nut, screw the nut to the bolt and the end to protect the thread, and then insert the internal expansion bolt into the hole.
3. Turn the wrench until the washer is flush with the fixture surface. If there is no special requirement, generally tighten it by hand, and then turn it with a wrench for three to five turns.
Three, the internal expansion bolt construction matters needing attention
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 internal expansion bolt left underground is equal to or less than the length of the expansion pipe.
2. Of course, the requirement of the internal expansion bolt on the ground is that the harder the better, which also depends on the stress of the object you need to fix. The mechanical strength of concrete (C 13- 15) is five times that of brick.
3. After an M6/8/ 10/ 12 internal expansion bolt is correctly installed in concrete, its most unsatisfactory maximum static stress is120/170/320/510 kg respectively.
The installation method of internal expansion bolt is not difficult, and the specific operation is as follows; First, choose an alloy drill with the same diameter as the expansion ring (tube) of the expansion screw, install it on the electric drill, and then punch the wall. The depth of the hole is preferably the same as the length of the bolt, and then the expansion screw set is lowered into the hole together, remember; When the hole is drilled deep and difficult to take out, do not unscrew the screw to prevent the bolt from falling into the hole. Then, tighten the nut for 2-3 times, and then unscrew the nut after feeling that the internal expansion bolt is tightened but not loosened. Then, install the bolt with holes on the fixed object, and install the outer washer or spring washer to tighten the nut.
Above, we have introduced three aspects of the information of the internal expansion bolt in detail, which are the text and picture contents of three plates: the introduction, installation steps and construction precautions of the internal expansion bolt. Through the study of the above knowledge, we know that the internal expansion bolt is a new type of internal expansion fastener, which can be divided into various specifications according to different application scenarios. Different brands and manufacturers also make it different in quotation and sales positioning.