Click image to view full size image
If you want to connect two separate steel structure components together, there must be a medium in between. The outer hexagon bolt is this medium. There are many types of hexagon bolts. According to the size of the bearing capacity, they can be divided into ordinary bolts and high-strength bolts. The hexagonal bolt is a very famous kind of bolts, but it can not be used casually. When installing high-strength hexagonal bolts, the bolts should be able to penetrate into the gap freely and unimpededly. If the size and position of the holes are not appropriate, do not force them. Penetrate. If you find that the hole diameter is smaller than the bolt diameter, you need to use an electric drill to make the hole larger.
http://www.hongdafastener.com/