What are the standard sizes of steel channels?

Steel channels come in various standard sizes, which are typically defined by their depth (height of the channel), flange width, and web thickness. These channels are commonly used in construction and structural applications. Below are some of the standard sizes for steel channels:

Common Types:
C-Channels (American Standard Channels, C Purlins)
U-Channels (Parallel Flange Channels, U Purlins)
1. C-Channels (American Standard Channels):
Designation Example: C 4 x 5.4
C: Indicates C-channel shape.
4: Depth of 4 inches.
5.4: Weight of 5.4 pounds per foot.
Standard Sizes:
Depth: Typically ranges from 3 inches to 15 inches.
Flange Width: Usually ranges from 1.41 inches to 4.06 inches.
Web Thickness: Typically varies from 0.17 inches to 0.5 inches.
Examples:

C 3 x 4.1: Depth of 3 inches, Flange width of 1.41 inches.
C 10 x 15.3: Depth of 10 inches, Flange width of 2.88 inches.
C 15 x 50: Depth of 15 inches, Flange width of 4.06 inches.
2. U-Channels (Parallel Flange Channels):
Designation Example: U 100 x 50 x 5
U: Indicates U-channel shape.
100: Depth of 100 mm.
50: Flange width of 50 mm.
5: Web thickness of 5 mm.
Standard Sizes:
Depth: Typically ranges from 30 mm to 400 mm (approximately 1.18 inches to 15.75 inches).
Flange Width: Usually ranges from 15 mm to 100 mm (approximately 0.59 inches to 3.94 inches).
Web Thickness: Typically varies from 4 mm to 15 mm (approximately 0.16 inches to 0.59 inches).
Examples:

U 100 x 50 x 5: Depth of 100 mm, Flange width of 50 mm, Web thickness of 5 mm.
U 200 x 75 x 8: Depth of 200 mm, Flange width of 75 mm, Web thickness of 8 mm.
U 400 x 100 x 15: Depth of 400 mm, Flange width of 100 mm, Web thickness of 15 mm.
Other Common Channel Sizes:
Depths: Can range from 20 mm (0.79 inches) to 400 mm (15.75 inches).
Weights: Vary depending on the size and type, often ranging from a few pounds per foot to several tens of pounds per foot.
These sizes represent standard options, but custom sizes can also be manufactured depending on specific project requirements.