Unfolded lateral surface of truncated at angle cone.
It is cut out on sheet metal with further circular rolling.

round air duct from metal sheet
Sheet thickness (s)
mm
Height (h) of truncated cone
mm
Outer diameter (D) of base of cone
mm
Angle (b) between the base and generatrices of the cone
°
The cutting angle (a) of the cone
°
Number (n) of split points
point
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