Unfolded curved surface of reinforcing pad of branch of duct tee
It is cut out on sheet metal with further circular rolling to fit the diameter (radius) of the tee header.

Reinforcing pad of vent branch. AutoCAD drawing.
Outer diameter (d) of tee branch
mm
Outer diameter (D) of tee header
mm
Width (h) of reinforcing pad
mm
Thickness (s) of reinforcing pad
mm
Number (n) of split points
point
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