S3M pulleys and belts are the best way to transmit power from your motor to drive wheels or a spinning weapon. Timing belts give better pulley grip than o-rings, which will slip.
We offer an extensive range of sizes and widths to provide options beyond common sizes/widths. This gives extra freedom when designing a bot.
Our belts are compatible with Fingertech S3M pulleys as well as other 3mm pitch pulleys.
•S3M pitch (3mm high-torque)
•Width: 4mm & 8mm
•Circumferences: 120mm (40T) - 408mm (136T).
Try our Belt and Pulley Calculator! Calculate your results for belt size, center to center distance or even pully sizes. It supports manual entry of pulley sizes if using sizes we don't stock.

Available Sizes and Widths
120mm, 40T Length: 4mm width
129mm, 43T Length: 4mm width
135mm, 45T Length: 4mm width
138mm, 46T Length: 4mm width
141mm, 47T Length: 4mm width
144mm, 48T Length: 4mm width
147mm, 49T Length: 4mm width
150mm, 50T Length: 4mm width
153mm, 51T Length: 4mm width
159mm, 53T Length: 4mm width
162mm, 54T Length: 4mm width
165mm, 55T Length: 4mm width
171mm, 57T Length: 4mm width
177mm, 59T Length: 4mm width
180mm, 60T Length: 4mm width
186mm, 62T Length: 4mm width
189mm, 63T Length: 4mm width
192mm, 64T Length: 4mm width
195mm, 65T Length: 4mm width
198mm, 66T Length: 4mm width
201mm, 67T Length: 4mm & 8mm width
207mm, 69T Length: 4mm width
210mm, 70T Length: 4mm & 8mm width
219mm, 73T Length: 4mm width
222mm, 74T Length: 4mm width
225mm, 75T Length: 4mm width
231mm, 77T Length: 4mm width
234mm, 78T Length: 4mm width
237mm, 79T Length: 4mm width
240mm, 80T Length: 4mm width
246mm, 82T Length: 4mm width
252mm, 84T Length: 4mm width
255mm, 85T Length: 4mm width
264mm, 88T Length: 4mm width
267mm, 89T Length: 4mm width
270mm, 90T Length: 4mm width
273mm, 91T Length: 4mm width
276mm, 92T Length: 4mm width
282mm, 94T Length: 4mm width
285mm, 95T Length: 4mm width
288mm, 96T Length: 4mm width
291mm, 97T Length: 4mm width
300mm, 100T Length: 4mm width
309mm, 103T Length: 4mm width
312mm, 104T Length: 4mm width
318mm, 106T Length: 4mm width
321mm, 107T Length: 4mm width
327mm, 109T Length: 4mm width
330mm, 110T Length: 4mm width
333mm, 111T Length: 4mm width
339mm, 113T Length: 4mm width
342mm, 114T Length: 4mm width
354mm, 118T Length: 4mm width
357mm, 119T Length: 4mm width
363mm, 121T Length: 4mm width
375mm, 125T Length: 4mm width
378mm, 126T Length: 4mm width
384mm, 128T Length: 4mm width
390mm, 130T Length: 4mm width
393mm, 131T Length: 4mm width
396mm, 132T Length: 4mm width
402mm, 134T Length: 4mm width
408mm, 136T Length: 4mm width