Timing Belt Idler Pulleys
Add these free-spinning pulleys to your timing belt setup to minimize vibration and keep belts from wearing out. The needle bearing at the center of these pulleys is lined with small, cylindrical rollers that reduce friction as they rotate. This bearing allows both the pulley and the shaft it’s mounted on to spin independently. Made from iron or steel, these pulleys are strong and wear-resistant. The black oxide coating protects the pulleys from corrosion in dry environments.
Curved teeth have more surface contact with belts than traditional trapezoidal teeth, which allows you to apply more torque without damaging belts. These teeth fit together seamlessly to prevent backlash, or unwanted movement of the belt on the pulley, for a smooth, quiet cycle. They are also known as curvilinear belt pulleys.
For technical drawings and 3-D models, click on a part number.



For Max. Belt Wd., mm | OD, mm | Number of Teeth | Teeth Shape | Pitch, mm | For Shaft Dia., mm | Dia., mm | Bore Type | Inside Wd., mm | Outside Wd., mm | Overall Wd., mm | Pitch Dia., mm | Number of Flanges | Fabrication | Material | Bearing Type | Hub Dia., mm | Each | |
For GT2 Belt Trade Size | ||||||||||||||||||
---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
21 | 90 | 32 | Curved | 8 | 20 | 79.88 | Plain | 21 | 31.5 | 45.97 | 81.48 | 2 | Machined | Black-Oxide Iron | Needle Roller | 69.85 | 0000000 | 0000000 |
37 | 146 | 30 | Curved | 14 | 40 | 130.89 | Plain | 37 | 52.32 | 58.67 | 133.68 | 2 | Machined | Black-Oxide Iron | Needle Roller | 111 | 0000000 | 000000 |
62 | 100 | 36 | Curved | 8 | 30 | 90.07 | Plain | 62 | 73.91 | 91.19 | 91.67 | 2 | Machined | Black-Oxide Iron | Needle Roller | 79.5 | 0000000 | 000000 |
High-Strength GT Timing Belt Pulleys
For higher speed or higher torque applications, these GT series timing belt pulleys provide a more precise fit than HTD pulleys. Use them where accuracy is critical, such as in storage and retrieval systems or in robotics. Similar to HTD timing belt pulleys, their teeth are curved for high strength. The curved teeth create positive grip engagement with timing belts, so these pulleys do not require re-tensioning—unlike drives using V-belts or sheaves. And unlike chain drives, there’s no metal-on-metal contact, so these pulleys don’t require lubrication.
Anodized aluminum pulleys are lightweight and resist corrosion. They have a finished bore and come with set screws for mounting on shafts.
For technical drawings and 3-D models, click on a part number.







Number of Teeth | Pitch, mm | For Shaft Diameter | Bore Type | Inside Width, mm | Outside Width, mm | Overall Width, mm | Pitch Diameter, mm | Number of Flanges | Fabrication | Material | Hub Diameter, mm | Each | |
For 6 mm Maximum Belt Width | |||||||||||||
---|---|---|---|---|---|---|---|---|---|---|---|---|---|
12 | 2 | 1/8" | Finished | 7.37 | 8.38 | 14.27 | 7.645 | 1 | Machined | Anodized Aluminum | 12.19 | 00000000 | 000000 |
14 | 2 | 1/8" | Finished | 7.37 | 8.38 | 14.27 | 8.915 | 1 | Machined | Anodized Aluminum | 13.46 | 00000000 | 00000 |
15 | 2 | 3/16" | Finished | 7.37 | 8.38 | 14.27 | 9.55 | 1 | Machined | Anodized Aluminum | 14.1 | 00000000 | 00000 |
16 | 2 | 3/16" | Finished | 7.37 | 8.38 | 14.27 | 10.185 | 1 | Machined | Anodized Aluminum | 14.73 | 00000000 | 00000 |
17 | 2 | 1/4" | Finished | 7.37 | 8.38 | 14.27 | 10.82 | 1 | Machined | Anodized Aluminum | 16.13 | 00000000 | 00000 |
18 | 2 | 1/4" | Finished | 7.37 | 8.38 | 14.27 | 11.455 | 1 | Machined | Anodized Aluminum | 16.13 | 00000000 | 00000 |
20 | 2 | 1/4" | Finished | 7.37 | 8.38 | 14.27 | 12.725 | 1 | Machined | Anodized Aluminum | 17.4 | 00000000 | 00000 |
24 | 2 | 1/4" | Finished | 7.11 | 9.91 | 17.45 | 15.291 | 2 | Machined | Anodized Aluminum | 11.23 | 00000000 | 00000 |
26 | 2 | 1/4" | Finished | 7.11 | 9.91 | 17.45 | 16.561 | 2 | Machined | Anodized Aluminum | 12.45 | 00000000 | 00000 |
28 | 2 | 1/4" | Finished | 7.11 | 9.91 | 17.45 | 17.831 | 2 | Machined | Anodized Aluminum | 12.55 | 0000000 | 00000 |
32 | 2 | 1/4" | Finished | 7.11 | 9.91 | 17.45 | 20.371 | 2 | Machined | Anodized Aluminum | 15.19 | 00000000 | 00000 |
36 | 2 | 1/4" | Finished | 7.11 | 9.91 | 17.45 | 22.911 | 2 | Machined | Anodized Aluminum | 17.17 | 00000000 | 00000 |
40 | 2 | 1/4" | Finished | 7.11 | 9.91 | 18.26 | 25.476 | 2 | Machined | Anodized Aluminum | 19.15 | 00000000 | 00000 |
48 | 2 | 1/4" | Finished | 7.37 | 10.41 | 18.26 | 30.556 | 2 | Machined | Anodized Aluminum | 23.77 | 00000000 | 00000 |
50 | 2 | 1/4" | Finished | 7.37 | 10.41 | 18.26 | 31.826 | 2 | Machined | Anodized Aluminum | 23.77 | 00000000 | 00000 |
60 | 2 | 1/4" | Finished | 7.37 | 10.41 | 18.26 | 38.202 | 2 | Machined | Anodized Aluminum | 31.04 | 00000000 | 00000 |
72 | 2 | 1/4" | Finished | __ | 9.65 | 19.05 | 45.847 | __ | Machined | Anodized Aluminum | 30.35 | 00000000 | 00000 |
100 | 2 | 5/16" | Finished | __ | 9.65 | 19.05 | 63.652 | __ | Machined | Anodized Aluminum | 38.1 | 00000000 | 00000 |
120 | 2 | 3/8" | Finished | __ | 9.65 | 19.05 | 76.403 | __ | Machined | Anodized Aluminum | 38.1 | 00000000 | 00000 |
For 9 mm Maximum Belt Width | |||||||||||||
16 | 3 | 3/16" | Finished | 10.16 | 11.43 | 17.55 | 15.291 | 1 | Machined | Anodized Aluminum | 18.03 | 00000000 | 00000 |
16 | 3 | 1/4" | Finished | 10.16 | 11.43 | 17.55 | 15.291 | 1 | Machined | Anodized Aluminum | 18.03 | 00000000 | 00000 |
17 | 3 | 1/4" | Finished | 10.16 | 11.43 | 17.55 | 16.23 | 1 | Machined | Anodized Aluminum | 18.8 | 00000000 | 00000 |
18 | 3 | 1/4" | Finished | 10.16 | 12.95 | 20.62 | 17.196 | 2 | Machined | Anodized Aluminum | 11.23 | 00000000 | 00000 |
20 | 3 | 1/4" | Finished | 10.16 | 12.95 | 20.62 | 19.101 | 2 | Machined | Anodized Aluminum | 12.7 | 00000000 | 00000 |
22 | 3 | 1/4" | Finished | 10.16 | 12.95 | 20.62 | 21.006 | 2 | Machined | Anodized Aluminum | 14.27 | 00000000 | 00000 |
24 | 3 | 1/4" | Finished | 10.16 | 12.95 | 20.62 | 22.911 | 2 | Machined | Anodized Aluminum | 15.88 | 0000000 | 00000 |
25 | 3 | 1/4" | Finished | 10.16 | 12.95 | 20.62 | 23.876 | 2 | Machined | Anodized Aluminum | 15.88 | 00000000 | 00000 |
26 | 3 | 1/4" | Finished | 10.16 | 12.95 | 20.62 | 24.816 | 2 | Machined | Anodized Aluminum | 15.88 | 00000000 | 00000 |
28 | 3 | 1/4" | Finished | 10.16 | 12.95 | 20.62 | 26.746 | 2 | Machined | Anodized Aluminum | 17.81 | 00000000 | 00000 |
30 | 3 | 1/4" | Finished | 10.16 | 12.95 | 20.62 | 28.651 | 2 | Machined | Anodized Aluminum | 19.71 | 00000000 | 00000 |
32 | 3 | 1/4" | Finished | 10.16 | 12.95 | 20.62 | 30.556 | 2 | Machined | Anodized Aluminum | 21.62 | 00000000 | 00000 |
34 | 3 | 1/4" | Finished | 10.16 | 13.46 | 21.16 | 32.461 | 2 | Machined | Anodized Aluminum | 23.39 | 00000000 | 00000 |
36 | 3 | 1/4" | Finished | 10.16 | 13.46 | 21.16 | 34.366 | 2 | Machined | Anodized Aluminum | 25.4 | 00000000 | 00000 |
40 | 3 | 1/4" | Finished | 10.16 | 13.46 | 21.16 | 38.202 | 2 | Machined | Anodized Aluminum | 29.21 | 00000000 | 00000 |
44 | 3 | 1/4" | Finished | 10.16 | 13.46 | 21.16 | 42.012 | 2 | Machined | Anodized Aluminum | 33.02 | 0000000 | 00000 |
45 | 3 | 1/4" | Finished | 10.16 | 13.46 | 21.16 | 42.977 | 2 | Machined | Anodized Aluminum | 31.75 | 00000000 | 00000 |
48 | 3 | 5/16" | Finished | __ | 12.7 | 22.26 | 45.807 | __ | Machined | Anodized Aluminum | 31.75 | 00000000 | 00000 |
50 | 3 | 5/16" | Finished | __ | 12.7 | 22.26 | 47.752 | __ | Machined | Anodized Aluminum | 31.75 | 00000000 | 00000 |
56 | 3 | 5/16" | Finished | __ | 12.7 | 22.26 | 53.467 | __ | Machined | Anodized Aluminum | 31.75 | 00000000 | 00000 |
60 | 3 | 5/16" | Finished | __ | 12.7 | 22.26 | 57.302 | __ | Machined | Anodized Aluminum | 31.75 | 00000000 | 00000 |
72 | 3 | 5/16" | Finished | __ | 12.7 | 22.26 | 68.758 | __ | Machined | Anodized Aluminum | 31.75 | 00000000 | 00000 |
80 | 3 | 5/16" | Finished | __ | 12.7 | 22.26 | 76.403 | __ | Machined | Anodized Aluminum | 31.75 | 00000000 | 00000 |
90 | 3 | 5/16" | Finished | __ | 12.7 | 22.26 | 85.954 | __ | Machined | Anodized Aluminum | 31.75 | 00000000 | 00000 |
100 | 3 | 5/16" | Finished | __ | 12.7 | 22.26 | 95.504 | __ | Machined | Anodized Aluminum | 31.75 | 0000000 | 00000 |
120 | 3 | 5/16" | Finished | __ | 12.7 | 22.26 | 114.579 | __ | Machined | Anodized Aluminum | 31.75 | 00000000 | 00000 |



Number of Teeth | Pitch, mm | ID | Bore Type | For Bushing Style | Inside Width, mm | Outside Width, mm | Overall Width, mm | Pitch Diameter, mm | Number of Flanges | Fabrication | Material | Each | |
For 40 mm Maximum Belt Width | |||||||||||||
---|---|---|---|---|---|---|---|---|---|---|---|---|---|
28 | 14 | 2.75" | Plain | Taper-Lock Style 2012 | 46.23 | 54.1 | 54.1 | 124.765 | 2 | Machined | Black-Oxide Iron | 00000000 | 0000000 |
46 | 14 | 3.375" | Plain | Taper-Lock Style 2517 | 46.23 | 54.1 | 54.1 | 204.978 | 2 | Machined | Black-Oxide Iron | 00000000 | 000000 |
72 | 14 | 4.25" | Plain | Taper-Lock Style 3020 | 46.23 | 54.1 | 54.1 | 320.853 | 2 | Cast, Machined | Black-Oxide Iron | 00000000 | 000000 |