Tolerances

5.00 PIC Gears are inspected on variable center distance equipment where they are meshed with a master gear under light checking pressure (tabulated below). As the gears rotate, center distance changes are greatly amplified and recorded on the PIC "True Blue" gear tapes as shown in Figure 5.1.

5.01 Refer to gear tolerance tables 5.2 and 5.3 for detailed gear tolerances. Individual "True Blue" tapes are available with PIC spur and bevel gears for a nominal additional charge based on the quantity involved.

Gear Testing Radius
5.02 Gear size is controlled by specifying a maximum and a minimum gear testing radius. The inspection trace must lie between these limits. The maximum limit for PIC stock gears is set at the theoretical pitch radius. The minimum limit is determined by the class of gear being cut.

Table 5.1 AGMA Fine - Pitch Gear Tolerances
AGMA Quality No.	No. of Teeth and Pitch Diam.	Diametral Pitch Range	Tooth-to-tooth Composite Tolerance	Total Composite Tolerance
10*	Up to 20 Teeth Over 20 Teeth Up to 1.999" Over 20 teeth 2" to 3.999" Over 20 teeth 4" and over	20 to 200 20 to 200 20 to 200 20 to 200	.0007 .0005 .0005 .0005	.0010 .0010 .0012 .0014
11	Up to 20 teeth Over 20 teeth Up to 1.999" Over 20 teeth 2" to 3.999" Over 20 teeth 4" and over	20 to 200 20 to 200 20 to 200 20 to 200	.0005 .0004 .0004 .0004	.0007 .0007 .0009 .0010
12**	Up to 20 teeth Over 20 teeth Up to 1.999" Over 20 teeth 2" to 3.999" Over 20 teeth 4" and over	20 to 200 20 to 200 20 to 200 20 to 200	.0004 .0003 .0003 .0003	.0005 .0005 .0006 .0007
13	Up to 20 teeth Over 20 teeth Up to 1.999" Over 20 teeth 2" to 3.999" Over 20 teeth 4" and over	20 to 200 20 to 200 20 to 200 20 to 200	.0003 .0002 .0002 .0002	.0004 .0004 .0004 .0005
14***	Up to 20 teeth Over 20 teeth Up to 1.999" Over 20 teeth 2" to 3.999" Over 20 teeth 4" and over	20 to 200 20 to 200 20 to 200 20 to 200	.00019 .00014 .00014 .00014	.00027 .00027 .00032 .00037
15	Up to 20 teeth Over 20 teeth Up to 1.999" Over 20 teeth 2" to 3.999" Over 20 teeth 4" and over	20 to 200 20 to 200 20 to 200 20 to 200	.00014 .00010 .00010 .00010	.00019 .00019 .00023 .00027
" Extracted from AGMA Gear Classification Manual for Spur, Helical and Herringbone Gears (Agma 390.02), with the permission of the publisher. The American Gear Manufacturers Association, 1330 Massachusetts Ave, N.W., Washington, D.C. 20005." AGMA 10 Similar to old PIC Standard Prec. 1 AGMA 12 Similar to old PIC Standard Prec. 2 **AGMA 14 Similar to old PIC Standard Prec. 3

Standard Tolerances Inch		Standard Tolerances Metric (all dimensions in millimeters)
Two place decimals	+/- .016	One place decimals	+/- 0.8
Three place decimals	+/- .005	Two place decimals	+/- 0.13
Fractional	+/- 1/32	Angles	+/- 1degree
Angles	+/- 1degree

Table 5.2 Gear Tolerances
AGMA Class Gear	P.D Tol.	O.D. Tol.	Bore Tol.	C.D. Fixed Centers	C.D. Adjustable Centers
Q-10 Q-12 Q-14	-.001 -.0007 -.0005	-.002 -.0015 -.001	+.0005 +.0003 +.0002	+.0005 +.0003 +.0002	+.002 +.0015 +.0012

Table 5.3 Fine-Pitch Gear Tolerances Table (All Dimensions in millimeters)
Pitch Diameter	Metric Module Range	Tooth-to-tooth Composite Tolerance µm	Total Composite Tolerance µm
Up to 12mm Over 12 to 50mm Over 50 to 100mm Over 100mm	Up to 0.6 Module	7 9 10 11	20 25 28 32
Up to 12mm Over 12 to 50mm Over 50 to 100mm Over 100mm	Over 0.6 Module	8 10 11 12	22 28 32 36
Up to 12mm Over 12 to 50mm Over 50 to 100mm Over 100mm	Up to 0.6 Module	5 5.5 6 7	14 16 18 20
Up to 12mm Over 12 to 50mm Over 50 to 100mm Over 100mm	Over 0.6 Module	5.5 6 7 8	16 18 20 22
Up to 12mm Over 12 to 50mm Over 50 to 100mm Over 100mm	Up to 0.6 Module	3.5 4 4.5 5	10 11 12 14
Up to 12mm Over 12 to 50mm Over 50 to 100mm Over 100mm	Over 0.6 Module	3.5 4.5 5 5	11 12 14 16