Steel connections are used to join two or more steel members together to form a stable and secure structure. The most common types of steel connections are bolted connections, welded connections, and riveted connections. Bolted connections are the most economical type of connection, but they are also the weakest. Welded connections are the strongest type of connection, but they are also the most expensive. Riveted connections are a hybrid of bolted and welded connections, and they offer a good balance of strength and cost.
The first steel connections were made using rivets. Rivets are metal pins that are inserted through holes in two pieces of steel and then hammered on the other side to create a tight joint. Riveted connections were strong and durable, but they were also time-consuming and labor-intensive to install. In the early 20th century, a new type of steel connection called the welded connection was developed. Welded connections are made by melting the edges of two pieces of steel together and then fusing them together. Welded connections are stronger than riveted connections and they can be installed more quickly. Today, most steel connections are made using welded connections.
The strongest type of weld is generally considered to be TIG welding, also known as Gas Tungsten Arc Welding (GTAW). TIG welding produces a very clean and precise weld, and the slow cooling rate that follows results in high tensile strength and ductility. MIG welding is also a strong candidate for the strongest type of weld because it can create a strong joint. However, the strength of a weld depends on a number of factors, including the material being welded, the skill of the welder, and the type of weld joint.
The main difference between a pinned and fixed steel connection is the ability to resist rotation. A pinned connection allows for free rotation between the connected members, while a fixed connection prevents rotation. Pinned connections are typically used in situations where flexibility is desired, such as in bridges and buildings that are designed to sway in the wind. Fixed connections are typically used in situations where stiffness is desired, such as in buildings that need to be able to withstand strong earthquakes.
To be a welder, you need to have good hand-eye coordination, attention to detail, and be able to follow instructions. Welding is a skilled trade that requires a lot of practice and attention to detail. If you are interested in becoming a welder, there are many apprenticeship programs and trade schools that can teach you the skills you need.