Round Idler Pulley and Round Drive Sheave Sizes

*These pulleys are actually cable pulleys. That is why the groove widths seem inconsistent. These pulleys work equally well for round belts, metal ropes and steel cables. They also work well with V-belts. See pictures of grooves at V Pulleys.

**Idler 5/16 x 2.13" is not available with drive adapter. It has a 6202 bearing -- 11 mm wide, 15 mm bore. Available only with .59" (15mm) bore diameter or .35" (8.9mm) bore adapter. All our other round and flat idlers use the 6203 bearing -- 12 mm wide, 17 mm bore, which fits all our bore adapters.

*** These are V-pulleys that work well with larger round belts. They will accommodate cross-section diameters up to 7/8"(22mm). Multiply the width at the bottom of the groove (the number in the R-column) by 2 to get the largest diameter that will fit in the pulley. These pulleys can be customized to meet your requirements. For example, the bottom of the groove dimension (root diameter) can be increased with urethane sleeves, and the flange dimension can be cut down to expose the belt. V-drive-pulleys can actually provide more drive than round pulleys because they can be sized to grip the cord harder by pinching it. Before buying large quantities, try one to make sure it meets your needs.

§ The narrow 3/8 x 3" idler pulley uses a R10ZZ bearing with a 5/8" bore. The bearing is 0.3438" wide. We do not have any bore adapters available for this pulley.

These round idler pulleys and round drive pulleys are designed for DuraBelt's round urethane, polyester and spring belts, but they also work well with rubber belts and steel cables.

Our round idler pulleys and round drive sheaves are made from nylon reinforced with fiberglass and ABEC-1 ball bearings. This nylon material is easy to machine on a lathe, and there is no fiberglass dust, as long as you do not grind it. We can cut down the flanges and/or add grooves (e.g. Poly-Vee grooves) at a slight extra cost.

When ordering by part number, specify either Idler or Drive, but not both.

Our idler pulleys can be converted to drive pulleys with our drive adapters. Click here for Round Pulley specs.

Maximum bore diameter:  idler pulleys = 17mm (0.669"), drive pulleys = 25.4mm (1")

For the best in round idler pulleys and round drive sheaves, insist on DuraBelt.