Drive pulleys made by machining or by assembling stampings are both alike and different.  Alike in that both can be cost-effective routes to high volume production, different in the tooling costs associated with their manufacture.  It is this difference in tooling costs that makes machined drive pulleys a logical choice for low volume production as well.

Stamped Pulleys

·        The combination of lower piece price and high tooling costs makes stamped drive pulleys more cost-effective as the production volume increases.

·        While stamped and assembled drive pulleys can provide adequate service in many applications care should be taken to identify any of the following potential difficulties:

o       Excessive speed - the tolerance on groove runout, side-to-side mismatch, and consequently balance are greater than for machined pulleys and split-formed pulleys.

o       Belt loads - should be lower than for one-piece pulleys to avoid any tendency for the halves to be forced apart.

o       Inadequate retention of hub to both pulley halves - both for torque transmittal and mechanical integrity.

·        It is difficult to provide corrosion protection between the pulley halves.

·        Stamped pulleys offer the advantage of rounded outer groove corners to prevent belt damage.

·        Consider using our existing stamped idlers as the basis for stamped drives.

Machined Pulleys

·        Machined pulleys can be cost-effective at lower volume than stamped or split-formed pulleys due to lower tooling cost. 

·        Piece price is determined by the equipment used to manufacture the product.

·        Size choice is "unlimited" as a result of the machining process.  Practically speaking, NHI can handle up to a Ø4" part from bar and up to Ø13" part by using slugs with our in-house equipment.

·        Where practical, leave as much material on the part as possible to minimize cycle time and therefore cost.

·        Machined pulleys can also be made into machined idlers.  Choose bearing sizes appropriate to the finished size of the part.

Contact NHI (solutions@nhipulleys.com or (800) 654-1090) today with your stamped pulley and machined pulley needs.