I-beam bolting techniques

Updated February 21, 2017

I-beam connections and assemblies have bolts joining the units together. Different bolting techniques can be used to accomplish a connection. A steel I-beam is used to construct buildings, bridges and other construction projects requiring steel construction beams. The I-beam is shaped like an I, hence the name, but also can be called the W-beam or H-beam, depending on the length of the flanges.

Shear Connection

The shear connection is one of the simplest bolting techniques used to join I-beams. A plate is aligned with each I-beam and a bolt hole is drilled through the plate and centre strut of the I-beam. Standard alloy bolts get used to attach a shear connection, but the size is determined by the thickness of the plates and centre strut, as well as how much weight the bolts will be expected to carry. The shear connection can be accomplished with a single plate, flexible end plate, angle cleat or bolted angle seat.

Moment Connection

The moment connection is used to attach the end of a horizontal I-beam to the flange of a vertical I-beam. A plate is generally welded to the end of the horizontal I-beam and aligned against the flange of the vertical I-beam. Holes get drilled through the end plate of the horizontal I-beam and flange of the vertical I-beam. Alloy bolts get inserted through the holes and tightened down to secure the connection. These type of bolting techniques can be called the bolted moment end plate, haunched end plate or flush moment end plate.


The I-beam splice is a common place where different bolting techniques can be used. Each I-beam end is butted together and a plate aligns against both I-beam ends. The plate is centred on the splice point. Holes are drilled through the plate and centre strut of both I-beams. Alloy bolts get inserted through the holes and tightened down. Sometimes additional plates are installed on the top and bottom flange of the splice point.

Concrete Connections

Many times during a construction project, I-beams require a connection to a concrete floor or wall. An expansion bolt with anchor ends is the bolting technique used to make this connection. A hole is drilled into the concrete and a special anchor end of the bolt is hammered into the hole. An end plate is installed on the I-beam and alignment holes are drilled through the end plate. The I-beam end plate holes are then aligned with the bolts inserted in the concrete. As the bolts are tightened to the I-beam end plate, the anchor end of the bolt begins to expand inside the concrete hole. The expansion of the anchor secures that end of the bolt tightly into the concrete, securing the I-beam to the concrete wall, beam or floor.

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About the Author

Mitchell Brock has been writing since 1980. His work includes media relations and copywriting technical manuals for Johnson & Johnson, HSBC, FOX and Phillip Morris. Brock graduated from the University of Southern California in 1980, earning a Bachelor of Arts in English.