BC- is the short form for bar channel section with parallel flanges. Their tolerances are defined by ASTM A 484.
In contrast to the MC-Channels series, flanges and webs have always the same material thickness. Although lower static values – with equal profile height – are achieved than with the MC-Channels, the BC-channels channels are seen as a low-cost alternative for a broad variety of applications as the specific weight per meter is low.
In addition channels with parallel flanges are much easier to assemble as no conical flat washer have to be used to compensate the natural conicity of the C-Channel’s flanges.