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Precision Sprockets Caliper Diameters per ANSI/ASME B29.1M

Tolerances for Caliper Diameters of Precision Chain Sprockets ANSI/ASME B29.1M

Caliper diameter is the same as the bottom diameter for a sprocket with an even number of teeth. For a sprocket with an odd number of teeth, it is defined as the distance from the bottom of one tooth gap to that of the nearest opposite tooth gap.

• The caliper diameter for an even tooth sprocket is equal to pitch diameter–roller diameter.
• The caliper diameter for an odd tooth sprocket is equal to caliper factor–roller diameter.
• Caliper factor = PD[cos (90° / N)], where PD = pitch diameter and N = number of teeth.
• Caliper factors for 1-in. pitch and sprockets having 9 to 108 teeth are given below in the table.

Caliper diameter tolerances are minus only and are equal to:

Commercial Spockets

Precision Spockets

Minus Tolerances for Caliper Diameters of Precision Chain Sprockets ANSI/ASME B29.1M

 Pitch Number of Teeth Up to 15 16 to 24 25 to 35 36 to 48 49 to 63 0.250 0.004 0.004 0.004 0.005 0.005 0.375 0.004 0.004 0.004 0.005 0.005 0.500 0.004 0.005 0.0055 0.006 0.0065 0.625 0.005 0.0055 0.006 0.007 0.008 0.750 0.005 0.006 0.007 0.008 0.009 1.000 0.006 0.007 0.008 0.009 0.010 1.250 0.007 0.008 0.009 0.010 0.012 1.500 0.007 0.009 0.0105 0.012 0.013 1.750 0.008 0.010 0.012 0.013 0.015 2.000 0.009 0.011 0.013 0.015 0.017 2.250 0.010 0.012 0.014 0.016 0.018 2.500 0.010 0.013 0.015 0.018 0.020 3.000 0.012 0.015 0.018 0.021 0.024 Pitch Number of Teeth 64 to 80 81 to 99 100 to 120 121 to 143 144 and up 0.250 0.005 0.005 0.006 0.006 0.006 0.375 0.006 0.006 0.006 0.007 0.007 0.500 0.007 0.0075 0.008 0.0085 0.009 0.625 0.009 0.009 0.009 0.010 0.011 0.750 0.010 0.010 0.011 0.012 0.013 1.000 0.011 0.012 0.013 0.014 0.015 1.250 0.013 0.014 0.016 0.017 0.018 1.500 0.015 0.016 0.018 0.019 0.021 1.750 0.017 0.019 0.020 0.022 0.024 2.000 0.019 0.021 0.023 0.025 0.027 2.250 0.021 0.023 0.025 0.028 0.030 2.500 0.023 0.025 0.028 0.030 0.033 3.000 0.027 0.030 0.033 0.036 0.039