Find W from the chordal thickness

Find the measurement W by the height and chordal thickness
Technical data	Input data
Normal module (Mn)		mm
Number of teeth (Z)		-
Helix angle (β)		deg.
Pressure angle (αn)		deg.
Tooth head diameter (Da)		mm
Height for chordal measurement (HC)		mm
Chordal thickness (SC)		mm
Number of teeth to measure (ZW)


Tangent measure of base found (W)		mm

Find the measurement W by the height and chordal thickness