The head of the hexagonal socket bolt is eccentric or skewed, which may cause serious problems. For example, from the appearance of the product, it is not aesthetically pleasing overall. Another issue is the eccentricity, which can easily cause the production tool to break easily. The most serious problem can also lead to a series of problems such as broken heads of hexagonal bolts.

Hexagon bolts are divided into ordinary and high-strength bolts according to their strength levels. Ordinary hexagonal bolts refer to grade 4.8, while high-strength hexagonal bolts refer to grades 8.8 and above, including grades 10.9 and 12.9. Grade 12.9 hex socket bolts generally refer to black hex socket cup head screws with knurled and naturally colored oil.