This small 24-tooth pulley is 1-1/16" long with 5/16" of that being a 5/8" dia shaft with a 1/2" x 3/8" flattened bore. The pulley portion is 1" OD x 7/8" ID. In shiny silver aluminum.

A nice pulley just ready to be combined into the block and tackle you need for tiny jobs, like trimming your bonsai trees or hauling your model boat out of the pond. Get this block with (1) sheave and rig up whatever you need. Each block has an aluminum frame about 3–1/2” long with “S” hooks on each end. The sheaves, or wheels are about 2” dia x 1/4” wide, with a “V” groove that looks perfect to handle 1/8” or smaller Venetian blind cord. These dudes are perfect for demonstrating mechanical advantage in the physics lab! But not for heavy lifting.

These translucent silicone O-rings are 3/32" thick and measure 4" dia. Nice belts for science-project motors and even nicer for our slingshot needs. Crafters will see jewelry material that the metal-detectors won't care about.

These translucent silicone O-rings are 1/8" thick and measure 3-1/2" dia. Nice belts for science-project motors and even nicer for your slingshot needs. Crafters will see jewelry material that the metal-detectors won't care about.

Steel. Not used but a little rusty from storage. Handy. Measures 3-1/2" dia with a single 1/2” ID sheave with a 2-1/8" x 1-5/8" dia hub and a keyed 1” ID bore. Drilled for a 1/4” - 16 setscrew (not included). Made in the USA.

This 32-tooth gear is 1-1/16" dia, 32 pitch and 20-degree pressure angle. Measures 3/32" thick on its face with a 1/4" bore and a 15/32" dia x 17/32" long 13-tooth shaft with the same pitch/pressure

Or gear down-for the science fair or for any number of hobby projects. This hard-to-find set of (3) combination spur/beveled gears-for when you want gears set either straight or at 90° to one another-also has one small spur gear, plus three bushings. All in red, green, or blue plastic (we'll pick). The combo-beveled gears are 1-5/8", 1-1/4" and 27/32" dia with 3/16" bores to accept the bushings, which are 3/16" OD, 3/32" ID. The straight gear is 17/32" dia with a 1/16" half-bore. All are 24 pitch.