03 Dec What are the Steel Beam Connection Types?

Steel structures are made up of numerous structural components that are assembled in different ways. Different structural products such as universal beams, universal columns, steel joists, box sections and steel channels all rely on different connections.

These connections are split into two main groups:

• Seated connections – where a steel beam is positioned on a seat, similar to that of masonry walls
• Framing connections – where the beam is connected to the supporting steel structure through a fitting. 

Different Types of Steel Beam Connections

• Bolted seat connections

  There are two types of bolted seat connections: stiffened and unstiffened. If there is a large reaction force at the end of the I beam, stiffened connection types are recommended as they have adequate capacity to resist these forces. If the forces aren’t big, unstiffened connection types should be used, as they have a limit to resist the forces.

  Seat connections are considered to be environmentally friendly as the structure with this connection can be taken down and the beams used elsewhere. They are also not expensive to fabricate.

• Bolted frame connections

  Here, structural steel beams are connected to the supporting elements such as a girder or a column, at a certain angle. The connection is usually calculated based on the loads at the end of the beam. Type, strength, the size of the fasteners and the strength of base materials are all taken into account when designing this type of metal connection. To guarantee stiffness and connection stability, the minimum length of the connection must be at least half the depth of the web. Read more about steel webs and flanges here.

• Welded seat connections

  These are very similar to bolted seat connections, except that here, welding is used rather than bolts, to fasten the steel beam elements. These can also be split into stiffened and unstiffened types. The stiffened type of welded seat connections are used in large loads, whereasthe unstiffened type is for smaller loads.

  However, these are not so kind to the environment as steel frame structures with this type of connection are not easily dismantled. One such example is steel frame buildings, which are designed to be durable and resistant in a single frame.

• Welded frame connections

  Various sizes of welded frame connections are available. In this type, the weld of the connection is subject to the direct stress and shear stress caused by loads on the steel beam that would affect the weld pattern. Part of the weld is carried out on-site, which makes a quality weld hard to achieve, as the steel components are susceptible to movement caused by wind and other factors. However, with the help of high-quality steel welding technology, on-site coded welders can perfect these connection components.

• End plate connections

  There are different types of end plate connections, including flexible, semi-rigid and rigid plate connections. The end plate is connected to the beam web (the vertical section) through the weld, since its size and capacity is dictated by shear capacity of the beam web which is connected to the weld. It is used to join, for example, a universal steel column to a beam, or a steel I beam to the flange of a girder or channel.

• Special steel beam connections

  These are used in situations where standard connections cannot be used. Examples of special connections include bent-plate framed, single web plate, one sided framed, balanced web plate and Z-type connection.