Pallet rack beams come in all types, styles, sizes, and variations. The most common way pallet rack beams are manufactured are either rolled form pallet rack beams or structural pallet rack beams. Here is a brief overview:

Rolled-formed pallet rack beams are manufactured by rolling coiled steel through a machine that shapes and welds the steel to create the beam.  The shape and welds give the pallet rack beam its strength and capacity.  Most roll-formed pallet rack, teardrop style being the most common, requires no fasteners for assembly.  This makes initial assembly easier and beam adjustment simple and quick.

Structural steel pallet rack beams are formed from hot-rolled steel and are a C-channel design.  They have greater capacity for the same size beam versus the rolled-form beam.  Structural steel is also much more damage resistant.  Because of its greater weight in steel it is more expensive than roll-formed rack.  Structural rack typically is bolt-together rack, sometimes called bolt-up rack, which requires attaching beams with fasteners.