Replacement thread-mount idler rotary shafts for chain and belt tensioning.
These thread into a tapped hole on a machine, wall, or bracket and give an idler sprocket or pulley a stub to rotate on. Pick a size below to load it into the configurator, the threaded mount, seat shoulder, idler-riding body, and (on the retaining-ring style) the ring groove are pre-dimensioned. Two end styles are offered: a retaining-ring end (zinc-plated 1215 carbon steel; ring and spacers included) and a shaft-collar end (hardened 1215; adjustable collar and grease fitting included). You stay in control of material, surface finish, tolerance class, and any added features. The drawing's title block stamps the source SKU, and we confirm full geometry against the catalog drawing or a sample before cutting.
Flange-mount idler shafts (with an integral bolt-circle flange) and the metric thread-mount sizes aren't on these cards yet, they're on our roadmap. Need one now? Send us a print or the old shaft and we'll quote it directly.
Thread-mount idler shaft sizes
Replacement thread-mount idler rotary shafts. They thread into a tapped hole to support idler sprockets and pulleys in chain and belt tensioning. Two end styles: a retaining-ring end (zinc-plated 1215, ring + spacers included) and a shaft-collar end (hardened 1215, adjustable collar + grease fitting included). Shaft and seat diameters, thread size and length, and groove dimensions are published per size; click a card to load a configurable starting point. Crosses the McMaster 2435K / 1816K thread-mount idler series.
It threads into a tapped hole on a machine, wall, or bracket and gives an idler sprocket or pulley a stub to rotate on, used to take up slack and tension chain or belt drives. The threaded end drives into the hole; a seat shoulder sets the standoff; the idler rides on the body. Two end styles are offered: a retaining-ring end (a ring and spacers position the component) and a shaft-collar end (an adjustable collar with a grease fitting).
Match the shaft (body) diameter to your idler's bore and the thread size to your tapped mounting hole, then check the overall length and standoff. If you're replacing a catalog part, the cards cross-reference the McMaster 2435K / 1816K series. Pick the card whose cross number matches.
Retaining-ring-end shafts are zinc-plated 1215 carbon steel with a machined ring groove; a retaining ring and spacers (included) hold the component in place. Shaft-collar-end shafts are hardened 1215 (about Rockwell C58) and ship with an adjustable shaft collar and a grease fitting so you can set the component width and lubricate it. Both load into the configurator with the threaded stud and body pre-dimensioned.
Retaining-ring-end cards default to 1215 free-machining carbon steel (zinc plating called out separately); shaft-collar-end cards default to hardened 1215 with a ground finish. Both are configurable. Switch material, heat treat, finish, or tolerance class in the configurator. Material certs (MTRs) are available on request.
The shaft and seat diameters, thread size and length, overall length, and (ring-end) groove dimensions are taken from the published catalog data. The axial split, where the seat shoulder sits and the groove location, is reconstructed from the dimension table and confirmed against the catalog 2-D drawing or a sample before we cut. The drawing title block stamps the source SKU so any deviation is visible.
Not yet from these cards. Flange-mount idler shafts (with an integral bolt-circle flange) and the metric thread-mount sizes are on our roadmap. For one of those today, send us a print or the old shaft and we'll quote it directly.
