HELICAL GEAR FORMULAS

HELICAL GEAR FORMULAS. . .

NO	TO FIND	HAVING	RULE
1	Transverse Diametral Pitch	Number of Teeth and Pitch Diameter	Divide the Number of Teeth by the Pitch Diameter
2	Transverse Diametral Pitch	Normal D.P. and Helix Angle	Multiply the Normal D.P. by the cosine of the Helix Angle
3	Pitch Diameter	Number of Teeth and Transverse D.P.	Divide the Number of Teeth by the Transverse D.P.
4	Normal Diametral Pitch	Transverse D.P. and Helix Angle	Divide the Transverse D.P. by the cosine of the Helix Angle
5	Helix Angle	Transverse D.P. and Normal D.P.	Divide the Transverse D.P. by the Normal D.P. — Quotient is the cosine of the Helix Angle
6	Transverse Pressure Angle	Normal P.A. and Helix Angle	Divide the tangent of the Normal P .A. by the cosine of the Helix Angle. Quotient is tangent of Transverse P.A.
7	Normal Circular Tooth Thickness	Normal Diametral Pitch	Divide 1.5708 by the Normal Diametral Pitch
8	Addendum	Normal Diametral Pitch	Divide 1 by the Normal Diametral Pitch
9	Outside Diameter	Addendum and Pitch Diameter	Add 2 Addendums to the Pitch Diameter
10A	Whole Depth (Coarser than 20 D.P.)	Normal Diametral Pitch	Divide 2.250 by the Normal Diametral Pitch
10B	Whole Depth (20 D.P. and Finer)	Normal Diametral Pitch	Divide 2.200 by the Normal D.P. and add .002
11	Clearance	Addendum and Whole Depth	Subtract 2 Addendums from the Whole Depth