ANSI/AGMA 1003-G93 pdf free.AMERICAN NATIONAL STANDA RD Tooth Proportions for Fine – Pitch Spur and Helical Gearing.
Greater clearance than given in tables 3 and 3M may be required if teeth are to be finished by a secondary operation. While the required clearance may vary with specific gear applications, a value of  0.350/Rnd (0.350 mn) shouIdprovidethe necessary amount in most cases. See ANSI B94.7—1966, Hobs; ANSI B94.21—1968, Shaper Cutters and AGMA 370.01 , Design Manual for Fine-Pitch Gearing.
The tooth thickness shown In the tables does not indude an allowance for bacidash when the gears are meshed at standard center distances.
In general, the teeth of both members are reduced In thicknesatoprovidobacldash. lncasesofplnbons having small numbers of teeth, consideration may be given to applying more of the tooth thickness reduction to the gear member to provide the required backlash. See ANSIIAGMA 2002-888 for a more detailed discussion of tooth thickness specification.
Allowance (thinning) for backlash must be considered to allow for kEwicant, temperatize effects, and operational meshing conditions induding deflections. bearing runouts, and gear element variations. For a detailed discussion see AGMA Paper 239.14, Assured Backlash Contros the ABC System, by Leonard J. Smith. [1 ]
NOTE – The design tooth thicluiesa Is established from engIneerIg consIderations. It I. determined by gear geometiy, gear tooth strength, and backlash. The methods for estabshing design tooth thickness, tar a given application, are beyond the scope of thIs standard.
3.7 Whole depth, h1
The whole depth values shown in the tables will increase in propodion to the amount of tooth thinning in cutting the teeth, unless the outside diameter Is also modified.
The whole depth of enlarged and reduced addendum gearing generated with pinion type shaper cutters may be different from that shown in the tables. In order to control the whole depth of external gears, the root cflameter should be specified as a maximum dimension only.
3.8 GeneratIng tools
Standard generating tools (hobs or shaper cutters) are used for either spur or helical gears. See ANSI B94.7—1966, Hobs, and ANSI 894.21—1986, Shaper Cutters.ANSI/AGMA 1003 pdf download.