Steel Channel sizes
There are two types of Steel channel sizes, one with designation MC and the other C as in steel steel c channel. The MC stands for miscellaneous channels range in sizes from 3 to 18 inches deep see figure 36 below. One of the most common usage of steel channel is on stair manufacture as stair stringers Similar to angle iron usage, the structural steel channel is mainly for light framing, though they can be used as main structural member such as beam or girder.
Another common application of steel channels is for supports of hanging loads such as mechanical units or fans hanging from roofing or floor framing.
If the span is 3 to 5 feet long, angle iron will work. For longer spans from 6 to 14 feet long +/-, steel channel will work best. But it all depends on the load.
If the load is too heavy even at 3 ft span, steel channel may be the best option.
Sometimes for heavier load it may be required to double up the steel channels or use wide flange with higher yield strength to be able to support the load.
Structural steel channels are also commonly used for light structure such as steel patio cover framing for carports commonly found at apartment complexes and/or light commercial structures. They can also be used at single homes like
figure 26 Similar to wide flanges or I beam designation, a MC18x58 is 18 inches deep and weighs 58 pounds per foot. Per figure 36 the W column is for weight in pounds per foot of the member. A is for cross sectional area of steel in square inches.
Sometimes if the load are too much for a single channel to carry, putting two channels back to back double it's capacity. The same way double angles are used.
Like angle iron, steel C channels, MC channels are A36 steel.