Compact Fairloc® 5 mm Pitch Timing Belt Pulleys

Product Announcement from Stock Drive Products & Sterling Instrument - SDP/SI

Hicksville, NY -- A series of thirty-four, 5 mm pitch timing belt pulleys, for 9 mm (.354") wide belts, manufactured by Stock Drive Products / Sterling Instrument feature the patented Fairloc® integral hub fastening system. The choice of the Fairloc® rotating component fastening system helps phase adjustment, timing, position adjustment and frequent removal problems while adding positive metal-to-metal fastening strength along the entire width of the pulley to reduce wobble or misalignment. It is compact, self-contained and offers a small pulley hub envelope.

How our Fairloc® Works:
The Fairloc® system consists of two slots that are machined into the aluminum hub, one orientated radially the other angularly, to create a transverse wedge which remains attached to the solid portion of the hub on one side. The resultant cantilevered clamping section has a tapped hole to accept a cap screw which passes through a clearance hole in the solid portion of the hub, and into a threaded hole in the transverse wedge section. As the screw is tightened the cantilevered section clamps the shaft securely. The screw can be tightened and released repeatedly without marring the shaft or affecting its torque transmitting abilities. The design offers the best of both worlds - the economy of the over-molded black fiberglass reinforced polycarbonate pulleys plus the positive fastening characteristics of metal-to-metal contact.

Identified as the A 6H 25 (inch) Series and the A 6H 25M (metric) Series are available from off-the-shelf stock in double or single flange styles. They are designed to fit onto shafts that range from 3/16" to 5/16" (4 mm to 8 mm) in diameter. The number of grooves per pulley ranges from 11 to 50.

Stock Drive Products / Sterling Instrument offers both inch and metric small off-the-shelf mechanical components for the design engineer. Thousands of stock components, in a wide variety of sizes can easily be located and purchased in one convenient place. The engineer not only meets all his component requirements, but saves valuable time by not having to search other sources. SDP/SI is your one-stop source for small mechanical components. Stock Drive Products / Sterling Instrument consistently provides high quality precision gears and gear assemblies in quantities for prototype to OEM’s. We make what others can’t.

Quotes, online orders, and 3D CAD models are available on our updated estore at

SDP/SI is a brand of Designatronics Inc.

Designatronics, Inc.
250 Duffy Avenue, Hicksville, NY 11801.
Phone: +1  516-328-3300