Modified Stock Gearing - Boston Gear

Internal Gears
48 through 16 Diametral Pitch (Brass)
14-1/2° Pressure Angle (will not operate with 20° spurs)
A
FACE
PITCH
DIA.
INSIDE
DIA.
OUTSIDE
DIA.
STANDARD TOLERANCES
DIMENSION TOLERANCE
48 Pitch All +.004 – .000
I.D. 32 Pitch All +.005 – .000
24 Pitch All +.006 – .000
16 Pitch All +.008 – .000
O.D. All +.001 + .003
ORDER BY CATALOG NUMBER
OR ITEM CODE
No. of Pitch Catalog Item
Teeth Dia. O.D. I.D. Number Code
48
DIAMETRAL PITCH FACE = .125"
48 1.000 1.500 .986 G632 12066
72 1.500 2.000 1.486 G633 12068
96 2.000 2.750 1.986 G635 12070
144 3.000 3.750 2.986 G637 12072
32
DIAMETRAL PITCH FACE = .188"
48 1.500 2.000 1.480 G664 12056
64 2.000 2.750 1.980 G666 12058
96 3.000 3.750 2.980 G668 12060
128 4.000 4.750 3.980 G669 12062
192 6.000 6.750 5.980 G670 12064
24
DIAMETRAL PITCH FACE = .250"
36 1.500 2.250 1.474 G675 12046
48 2.000 2.750 1.974 G677 12048
72 3.000 3.750 2.974 G679 12050
96 4.000 4.750 3.974 G680 12052
144 6.000 6.750 5.974 G681 12054
16
DIAMETRAL PITCH FACE = .313"
32 2.000 2.750 1.962 G689 12038
48 3.000 3.750 2.962 G691 12040
64 4.000 4.750 3.962 G692 12042
96 6.000 6.750 5.962 G693 12044
GEAR
PITCH DIA.
(D)
PINION
PITCH DIA.
(d)
CENTER DISTANCE
CENTER
DISTANCE =
D – d
2
NOTE: The difference in tooth numbers between Gear and Pinion
should not be less than 15.
36 Boston Gear 800-825-6544 P-1930-BG 04/10