Stock Drive Products/Sterling Instrument (SDP/SI) is a leading manufacturer of synchronous drive components for small power transmission and motion control applications. Established in 1950, SDP/SI has been supplying the world with timing belts and pulleys, in both inch and metric sizes, and the engineering expertise to guarantee the best possible drive system.

Not only does SDP/SI keep a large assortment of standard timing belts on-the-shelf,  but has the capability to cut custom widths on demand from existing belt material in inventory. Available profiles include: Miniature FHT®, MXL, 40 D.P., XL, L, HTD®, GT®2, GT®3, and T.

Timing Belt Pulleys, molded or machined, are manufactured to ensure proper operation and long belt life. Our pulleys are precisely machined to run perfectly with the various timing belt profiles offered. 

Whether you're looking for a replacement timing belt or creating a new design, you're sure to find the perfect standard or custom timing belt and pulleys from our huge selection. Small to large quantities - request a quote today.

Stock Drive Products/Sterling Instrument (SDP/SI) is ISO 9001 + AS9100 certified, providing solutions for motion control and small power transmission applications. SDP/SI offers both stock and custom small mechanical components and assemblies. Get standard mechanical components online. Extensive technical data is available, such as Designing a Miniature Belt Drive, Drive Comparative Studies, Design and Installation Suggestions, Belt Construction, and much more.

Quotes, online orders, and 3D CAD models are available on our updated estore at www.sdp-si.com/estore.

Stock Drive Products/Sterling Instrument, a Designatronics, Inc. company 
250 Duffy Avenue, Hicksville, NY 11801
Phone: +1  516-328-3300
www.sdp-si.com