The Channel Section shape is the outline of a rolled steel channel (C channel, PFC): a web with a flange at each end, both flanges on the same side. It is sized the way section tables give it – Depth, Width, Web Thickness, Flange Thickness, Root Radius and Toe Radius – with an optional Flange Slope for taper flange channels. Use it to cut a channel-shaped profile, for example a template or an end plate that matches a channel. It is one closed outline. In search it is also found as Channel, C Channel and PFC.
It appears in the shapes library under Other Shapes.
Channel Section in PrimeShape: the property page (left) and the shape with its dimensions (right).
Insert point and direction
The web is on the left and the flanges point to the right (+X). The insert point (Base X, Base Y) is the bottom left corner of the section: the back of the web at the underside of the bottom flange. The section extends Width to the right of the insert point and Depth upward.
The profile is built anticlockwise from the insert point: along the underside of the bottom flange, up the flange tip, back along the inside face of the bottom flange, round the root fillet and up the inside face of the web, round the top root fillet, out along the inside face of the top flange, up the flange tip, and back across the top and down the back of the web.
Only the four inside corners are rounded: the Root Radius where each flange meets the web, and the Toe Radius on the inside edge of each flange tip. The outside corners (back of the web and outer edges of the flange tips) are always sharp.
The dimensions drawn on the shape are named after their properties, so clicking one edits that value. Depth is dimensioned up the left side, along the back of the web, Width along the bottom, Web Thickness across the web at mid depth, and Flange Thickness on the top flange half way along the outstand. Root Radius and Toe Radius are dimensioned on the top fillets; each is hidden when it is 0, and both are hidden when the radii are too large to fit.
Properties
Property |
Description |
Default |
Depth |
Overall depth of the section, along Y, from the underside of the bottom flange to the top of the top flange (length). |
200 mm (8 in when working in inches) |
Width |
Overall width of the section, along X, from the back of the web to the flange tips (length). The flange outstand is Width minus Web Thickness. |
75 mm (3 in) |
Web Thickness |
Thickness of the web (length). Must be greater than 0 and less than Width. |
6.25 mm (0.25 in) |
Flange Thickness |
Thickness of each flange (length). With a Flange Slope it is measured half way along the flange outstand, as section tables give it; the flange is then thicker at the web and thinner at the tip. |
12.5 mm (0.5 in) |
Root Radius |
Radius of the inside fillet where each flange meets the web (length). 0 gives a sharp corner. |
12.5 mm (0.5 in) |
Toe Radius |
Radius on the inside edge of each flange tip (length). 0 gives a sharp corner. |
0 |
Flange Slope |
Slope of the inside face of each flange, for taper flange channels (angle, 0 to 45 degrees). 0 gives parallel flanges (PFC). The flange thickness changes by tan(Flange Slope) × outstand / 2 each side of Flange Thickness: thinner at the tip, thicker at the web. |
0 degrees |
The default is about the size of a 200 x 75 parallel flange channel.
Limits
The property page shows Warning: Cannot build shape from these parameters and no outline is drawn when any of these is true:
•Depth or Width is 0 or less.
•Web Thickness or Flange Thickness is 0 or less.
•Web Thickness is equal to or greater than Width.
•Flange Slope is less than 0 or more than 45 degrees.
•Root Radius or Toe Radius is negative.
•The Flange Slope is so steep that the flange tips have no thickness (Flange Thickness minus tan(Flange Slope) × outstand / 2 is 0 or less, to within a small tolerance).
•The flanges are too thick for the Depth: twice the flange thickness at the web is equal to or greater than Depth, leaving no inside face on the web.
•Root Radius or Toe Radius is too large: the fillets at the two ends of a side need more length than the side has. For example, the root fillet and the toe fillet must both fit along the inside face of a flange, and the two root fillets must both fit along the inside face of the web.
To point the flanges another way, set Rotation or Mirroring X in the Transform properties. For an I beam, angle or tee, use the I Beam Section, Angle Section or Tee Section shapes. They are sized with the same Depth and Width, but an angle has one Thickness for both legs and no Flange Slope.
Every 2D shape also has the Transform properties (Base X, Base Y, Rotation, Scale, Mirroring X) and the Polar Array properties, listed after the shape's own properties.