Synchronous Idler Sprockets (HTD & Poly Chain GT2)
htd idler sprockets (ball bearing)

part # | pitch / belt width | # of grooves | a | b | c | i | approx. weight (lbs) |
29-8m-50bb | 8mm / 50mm | 29 | 2.859" | 2 1/8" | 3/4" | 1/16" | 3.5 |
29-8m-85bb | 8mm / 85mm | 29 | 2.859" | 3 1/2" | 3/4" | 1/16" | 5.0 |
27-14m-40bb | 14mm / 40mm | 27 | 4.627" | 1 11/16" | 1" | 1/16" | 4.1 |
27-14m-55bb | 14mm / 50mm | 27 | 4.627" | 2 3/8" | 1" | 1/16" | 9 |
27-14m-85bb | 14mm / 85mm | 27 | 4.627" | 3 9/16" | 1 3/8" | 1/16" | 12 |
31-14m-115bb | 14mm / 115mm | 31 | 5.33" | 4 13/16" | 1 1/2" | 1/16" | 19 |
radial load capacity in lbs
based on 2500 hours service life at rpm shown
part # | 100 RPM | 500 RPM | 1000 RPM | 1200 RPM | 1800 RPM |
29-8m-50bb | 2336 | 1366 | 1084 | 1020 | 891 |
29-8m-85bb | 2336 | 1366 | 1084 | 1020 | 891 |
27-14m-40bb | 2555 | 1494 | 1186 | 1116 | 975 |
27-14m-55bb | 2555 | 1494 | 1186 | 1116 | 975 |
27-14m-85bb | 6113 | 3575 | 2837 | 2670 | 2332 |
31-14m-115bb | 6113 | 3575 | 2837 | 2670 | 2332 |
htd idler sprockets (needle bearing)

part # | brewer interchange |
pitch / belt width | # of grooves | a | b | c | i | approx. weight (lbs) |
19-8m-30nb | p19-8m-30f | 8mm / 30mm | 19 | 1.851" | 1 3/8" | 1" | 1/16" | 0.69 |
29-8m-50nb | p29-8m-50f | 8mm / 50mm | 29 | 2.859" | 2 1/2" | 1" | 1/16" | 3.7 |
29-8m-85nb | p29-8m-85f | 8mm / 85mm | 29 | 2.859" | 3 1/2" | 1" | 1/16" | 5.3 |
27-14m-40nb | p27-14m-40f | 14mm / 40mm | 27 | 4.627" | 1 11/16" | 1" | 1/16" | 5 |
27-14m-55nb | p27-14m-55f | 14mm / 55mm | 27 | 4.627" | 2 3/8" | 1" | 1/16" | 11 |
27-14m-85nb | p27-14-85f | 14mm / 85mm | 27 | 4.627" | 3 9/16" | 1" | 1/16" | 14 |
31-14m-115nb | p31-14m-115f | 14mm / 115mm | 31 | 5.33" | 4 13/16" | 1 1/2" | 1/16" | 22 |
radial load capacity in lbs
based on 2500 hours service life at rpm shown
part # | 100 RPM | 500 RPM | 1000 RPM | 1200 RPM | 1800 RPM |
19-8m-30nb | 4483 | 2766 | 2247 | 2127 | 1883 |
29-8m-50nb | 6266 | 3867 | 3141 | 2973 | 2633 |
29-8m-85nb | 6266 | 3867 | 3141 | 2973 | 2633 |
27-14m-40nb | 6266 | 3867 | 3141 | 2973 | 2633 |
27-14m-55nb | 6266 | 3867 | 3141 | 2973 | 2633 |
27-14m-85nb | 12249 | 7558 | 6139 | 5812 | 5147 |
31-14m-115nb | 12249 | 7558 | 6139 | 5812 | 5140 |
htd idler sprockets (ball bearing)

part # | gates interchange |
belt width (mm) |
no. of teeth |
o.d. | b ref |
c | d | e ref |
f threads |
g ref |
h | j | app weight (lbs) |
8m-32s-12-bb | 12-idl-spk2 | 12 | 32 | 3.15" | 1.68" | 0.50" | 0.85 | 1.56" | 3/4"-16 | 0.94" | 2.52" | - | 1.0 |
8m-32s-21-bb | 21-idl-spk2 | 21 | 32 | 3.15" | 1.68" | 0.50 | 1.24 | 1.56" | 3/4"-16 | 0.56" | 2.75" | - | 1.2 |
8m-36s-36-bb | 36-idl-spk2 | 36 | 36 | 3.55" | 1.68" | 0.75 | 1.86 | 1.63" | 3/4"-16 | - | - | - | 2.0 |
8m-36s-62-bb | 62-idl-spk2 | 62 | 36 | 3.55" | 1.68" | 0.75 | 2.91 | 1.69" | 3/4"-16 | 0.69" | 3.13" | - | 2.2 |
14m-30s-20-bb | 20-idl-spk2 | 20 | 30 | 5.15" | 1.68" | 1.00 | 1.36 | 2.25" | 1"-14 | 1.00" | 4.38" | - | 9.0 |
14m-30s-37-bb | 37-idl-spk2 | 37 | 30 | 5.15" | 1.68" | 1.00 | 2.06 | 2.25" | 1"-14 | 0.25" | 4.38" | - | 12.0 |
14m-34s-68-bb | 68-idl-spk2 | 68 | 34 | 5.86" | 1.68" | 0.56 | 3.33 | 2.25" | 1"-14 | 1.00" | 4.38" | 4.34" | 15.6 |
14m-34s-90-bb | 90-idl-spk2 | 90 | 34 | 5.86" | 1.68" | 0.31 | 4.20 | 2.25" | 1"-14 | 1.00" | 4.38" | 4.34" | 17.0 |
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