Xem Studiomeasured geometry

Library › Hardware › C channels (AISC American Standard channels): C6x13, C8x11.5…

C12 x 20.7 channel

C12 x 20.7 channel: depth 12.0 in (304.8 mm), flange 2.94 in (74.7 mm), web 0.282 in, mean flange 0.501 in, flanges sloped 2 in 12 in, 4 in long

Exact dimensions. True size, no printing tolerance added. Threads are plain cylinders at the major diameter.

STEP STL free, CC BY 4.0 (credit "Xem Studio")

Dimensions

shapeC12x20.7
lb/ft20.7
d (in)12.0
bf (in)2.94
tw (in)0.282
tf mean (in)0.501
k (in)1.13
d (mm)304.8
bf (mm)74.7
tw (mm)7.16
tf (mm)12.73
Let your AI pull this. Add https://xemstudio.com/mcp to Claude, ChatGPT, Cursor or any MCP client (free, no account, one minute) and it can look up exact sizes, mating fits and free STEP/STL from every chat.
Set it up →

From the full sheet

C channels (AISC American Standard channels): C6x13, C8x11.5, C12x20.7 dimensions + STEP/STL: every size, notes, mating features and sources. What are the dimensions of a C6x13 channel?

Other sizes