steel-to-steel connection methods

What Are The Methods of Joining Structural Steel?

In the world of steel-to-steel connections, there are a myriad of options and avenues to consider when joining structural steel components together. While it’s certainly true that every method has its own strengths, weaknesses, and ideal circumstances where its potential can be maximized, there are also plenty of ways some connections could be considered better than others.

Steel-to-steel connections have been commonplace in construction since the 1920s, with the introduction of monolithic steel skyscrapers: symbols of progress, urbanization, and the economic development of the 20th century.

Due to that long and illustrious history, a wide variety of methods have been devised to harness the power of steel, sturdily connecting these components together to create ever-larger and more durable structures from the early 20th century to today. However, not all steel-to-steel connection methods are created equal.


While we’ve all heard the phrase “modern problems require modern solutions”, one solution that’s been consistently in use since the inception of steel-to-steel connections is welding. While the idea of using heat to bond metal components together has been in use for centuries, the first modern welding implements used in the steel industry were invented following the discovery of acetylene gas in 1836 by chemist Edmund Davy. 1881 marks the inception of modern welding, as the gas-powered arc welder was first created by a Russian inventor named Nikolay Benardos.

While it wouldn’t be used in buildings until the 1920s, welding is still a premier method of bonding steel components together even today. That’s true even though new technology and advancements in engineering have since produced better-looking, simpler-to-install, and easier to replace solutions.

Put very simply, welding uses heat to meld steel components together, joining them as they’re melted into one another. The result is a strong connection; but skilled labor, specialized equipment, and damage to the steel components are all required. While welding is still widely in use, it’s safe to say there are simpler, more practical, cost-effective, and better looking options to join steel components today.


Much like welding, riveting was a very common method of steel-to-steel connection in the early 20th century, gradually being replaced by bolts by the late 1950s. Although bolts would go on to largely replace them, the principle of how riveted connections are joined together is very similar. Much like bolts, rivets involve holes to be drilled in each steel component. However, unlike bolts, a combination of heat and pneumatic pressure supplied by a specially designed rivet gun is needed to push the rivets into place; although time and energy-consuming, the result is incredibly durable.

From bridges, to buildings, and even bomber-planes, rivets were widely used in American manufacturing and construction throughout the first half of the 20th century, but several limitations contributed to their eventual replacement. Considering a specialized device, the rivet gun, is required to install rivets, their implementation is a loud, and somewhat costly process that is difficult to undo in order to fix mistakes or make adjustments.

While there are many methods that can be used to remove rivets, it takes particular care and skill to remove them in a fashion that preserves the hole for re-insertion outside of using a specialized rivet-removal tool, creating an additional expense. Rivets allow many of the same benefits as bolts, but the latter’s dramatically lower cost and skill required for installation meant they were eventually replaced altogether. Considering that even small welds generally provided the same structural durability as riveting, it’s no wonder riveting eventually became obsolete, leaving welding and bolting to be the primary means of steel-to-steel connections.


Bolts are the primary means of steel to steel connections today, and have achieved this status through their universally-understood ease of use, and overall design simplicity. Another major advantage is their ability to be tightened with ease to reinforce a connection, or removed altogether to be replaced, or (in some circumstances) reused.

Compared to welding, bolting offers a much more aesthetically pleasing solution and is of more consistent strength since the strength of a weld is largely dependent on its quality. It’s for these reasons that bolting swiftly became the world’s dominant steel-to-steel connection solution, but that isn’t to say that conventional bolting methods are without flaws and limitations.

For instance, although bolts offer unparalleled flexibility with their ease of installation and removal, their installation method, requiring screw-like grooves which allow the body of the bolt to travel into an appropriately-sized hole, can make them susceptible to unscrewing due to heavy vibrations, such as trains passing over a bolt-constructed bridge. Because of this, bolted connections sometimes must be maintained through occasional tightening.

Another limitation of traditional bolted connections is that both sides of the steel components being attached need to be accessible. For the longest time, this was the single area where bolted connections simply couldn’t surpass riveting, but advancements in bolted-connection engineering have resulted in new types of bolts, and other steel-to-steel connection implements that offer further advantages in strength and durability while providing a solution for even the most ambitious of structural connections.


Needless to say, over what has been roughly a century of steel-to-steel connections being a vital component of construction products around the world, the technology and methods used to do so are always improving and evolving, and LNA Solutions offers a wide range of different bolt-related technologies as a result.


While more complicated than a regular bolt, the key use and advantage of BoxBolts® are their ability to attach hollow structural sections (HSS) of steel, as well as any other circumstance where one side of the connection is inaccessible. This was something rivets could accomplish, but BoxBolts® accomplish this same feat with ease while providing all of the numerous advantages of bolted connections, such as ease of installation and removal.

Before BoxBolts®, most steel to steel connections where one side is inaccessible needed to be welded, or accomplished by using a “through bolt”, requiring the use of two people. However, BoxBolt’s® unique sheathed design means blind structural connections can be easily achieved through the efforts of just one person, with little to no specialized training.

BoxBolts function like this: As the nut of the bolt is tightened by a wrench, the body actually travels upward towards that nut. As it does this, it causes panels located on a sheath over the body to expand outward. The resulting action pins both steel sections together, between the nut and the expanded sheath panels; a self-contained solution that can be achieved simply through tightening the nut like any other bolt.

Outside of saving time and money, BoxBolts® are also corrosion resistant, and come in three distinct coatings, giving them the ability to withstand a wide variety of environmental conditions.


If a steel-to-steel connection needs to be reinforced, making them resistant to heavier weight demands and gradual unscrewing due to intense vibrations, LNA Solutions also offers a range of products known as BeamClamps®.

The function of BeamClamps® is in the name: used to affix two steel beams together without the need for welding or riveting, BeamClamps® clamp down on the beams with teeth-like grooves to establish a secure, unyielding connection.

This connection is all achieved through external apparatus, meaning the beams themselves remain undamaged. The result is a secure connection with immense weight-bearing potential that doesn’t compromise the easy-to-adjust appeal of bolted connections.

Similar to BoxBolts®, BeamClamps® are designed to adhere two steel sections together, in this case, girders and beams, without physically bonding them together. This ensures a non-destructive, aesthetically pleasing connection that is immensely durable.


Throughout the history of steel-to-steel connections, methods such as welding and bolting have distinguished themselves through decades of use and technical refinement, and while those traditional methods will always have their place, in the roughly one hundred years of modern steel-to-steel methods are constantly evolving and new ones, developing.

Today implements such as BoxBolts® and Beam Clamps® help to expand the versatility and potential of bolted connections further as the dominant medium in steel-joining technology, an area that will only continue to advance.


If you’re interested in maximizing the potential of bolted connections through maximizing the efficiency of blind connections or the load-bearing potential of beam-based connections, look no further than the range of products offered by LNA Solutions. If you’d like to learn more about the implements and solutions we offer to streamline and strengthen your steel-to-steel connection needs, please refer to our product page.



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structural beam clamp connections during construction