The concrete self tapping bolt adopt one type design , which is a heavy load anchor bolt . It has the features of simple installation , easy recognition , disassembly and vibration resisitance . This bolt has a number of unique designs suitable for a variety of substrates. The traditional expansion bolt has the external expansion, which can easily cause the crack of the base material . This anchor bolt overcomes these shortcomings, saves time and labor , and also does not need complex installation steps .