A self-drilling anchor bolt is a new and efficient engineering support material. In foreign countries, self-drilling anchor bolts are widely used in foundation support, foundation pit reinforcement, slope protection, tunnel advance support, etc., and can be used as micro piles, rock bolts, ground anchors, soil nails, etc. It consists of six important parts: drill bit, hollow bolt body, connecting sleeve, backing plate, nut, and centering device, which can efficiently drill and construct under the conditions of easy-to-collapse holes.

 

 

First of all, here is a mistake to correct everyone. The diameter of the self-drilling anchor bolt construction hole is not directly related to the diameter of the bolt but is determined by the diameter of the drill bit adapted to the bolt.

 

Secondly, due to the different geological conditions of each project, the drill bits are also varied. I will take the following six commonly used drill bits as examples to introduce how to determine the diameter of the self-drilling anchor bolt hole.

 

Cross all-steel drill bit: There are many types of this drill bit, its diameter is from 42mm to 175mm, and it can be adapted to rod diameters ranging from 25mm to 76mm.

 

Cross alloy drill bit: The cross alloy drill bit of model HSR25/42 has a hole diameter of 42mm and a diameter of 25mm for the rod body. The rod bodies are 76mm and 52mm respectively. That is to say, the diameter of self-drilling anchor bolts equipped with cross alloy bits is 42~200mm.

 

Clay bit: The clay bit adapts to the geological conditions of the soft soil layer, and the maximum diameter of the drill hole can reach 300mm and the minimum is 76mm. Self-drilling anchor bolts are equipped with different types of clay bits, and the diameter of the drilled holes is also quite different.

 

Ball tooth all-steel drill bit: This type of drill bit has a drilling diameter range of 42~130mm, and can be adapted to self-drilling anchor bolts with a diameter of 25~76mm.

 

Ball-tooth alloy drill bit: The minimum drilling diameter of this type of drill is 42mm and the maximum is 200mm, and the diameter of the suitable rod body is 25~76mm.

 

Steel plate drill bit: The rigid plate drill bit is a straight-line drill bit. If the diameter of the self-drilling anchor bolt is 51mm, the corresponding type of steel plate drill bit can have a drilling diameter of 130mm; when used in conjunction with a 25-diameter bolt. The diameter is 50mm.

 

In a specific construction project, we should first determine the diameter of the self-drilling anchor bolt and then match the drill bit accordingly. Once these two components are determined, the diameter of the construction hole is determined. Moreover, in the project support construction, the diameter of the drill hole is generally determined in the design process, that is to say, the design unit will determine the diameter of the drill hole according to the measurement results, and the construction personnel only need to find the self-drilling anchor bolt that can meet the required diameter of the drill hole Sinorock self-drilling anchor bolt manufacturer produces a variety of drill bits, the diameter of which is from 25mm to 300mm, which can meet the needs of most engineering construction.