1、 Appearance design and construction

Bolt is a kind of permanent mechanical equipment standard parts. Prior to installation, the bolt consists of a smooth cylindrical shaft with a crown at one end. The opposite end of the head is called the tail end. During installation, the bolt is placed in the punching machine or punching hole, and the tail end is upset or bent (i.e. deformation), so that it expands to 1.5 times of the original shaft diameter, and the bolt is fixed at an appropriate position. That is to say, according to the broken "little tail", a new "top of the head" is created at the other end according to the impact, and then a new substance which is about barbell shaped is produced.

There are many kinds of bolts, which can be divided into solid core / round mouth screw, half pipe bolt, blind bolt, driver bolt and friction clamp bolt. The surface layer can be hot-dip galvanized, nickel, copper, tin and other coatings.

Bolts can be made of aluminum, titanium, nickel base superalloy (such as Monel alloy), high toughness alloy structural steel and other raw materials. For high toughness alloy structural steel, double drum rivet is divided into three grades according to composition and three grades according to strength in ASTM a502-3 (standard standard for alloy structural steel rivets).

2、 Principle and Application

Each top of the bolt has a top part, which is fixed. After the machine and equipment, it can support the tension load of the point. Unlike the appropriate supporting force load of the anchor bolt and screw, the automobile core pulling rivet can support the cutting load of the point (the load of the vertical bisector axis).

Before the development and design of welding technology and screw connection, metal material frame building structures such as the Eiffel Tower in Paris, the Golden Gate Bridge and the London port overpass were riveted together, and the chassis was the same.