Bushings are one of most integral components in a roller chain that plays a huge factor in overall performance & service life. There are two different roller chain bushing types used to build roller chains, which are split bushings & solid bushings. Below we explain the two different bushing styles and the impact they have in a roller chains quality. Nitro® roller chains are now being manufactured with the cold-forged solid bushings & rollers.**
Fun Fact: Roller chain does not technically stretch. What really happens is chain elongates due to wear (material loss) on the pin and bushing.
Solid Bushing Roller Chain
The solid bushings are manufactured from cold-forged carbon steel to a true cylindrical shape. Unlike split bushings, the solid bushing maintains it's shape when being pressed into the link plate. The solid bushing has even contact throughout the pin/bushing are (as pictured above), which reduces the bearing pressure points that results in less wear over time. Solid bushings can offer service life 2x-3x longer than a split bushing chain.
Solid Bush Overview:
- Maintains it's shape even under heavier loads
- Even pin/bushing contact for less wear
- Retains lubrication better
- Longer service life
Split Bushing Roller Chain
Split bushings are made from strip steel that are curled into the form of a bushing. This lacks rigidity and leads into a "barreling" effect when the bushings are pressed into the inner link plates. There are two common problems associated with the barreling effect. The first issue is the pin/bushing area develops four pressure points as shown in the image. As a result the load is not evenly dispersed across the entire pin/bushing surface, so those pressure points will wear faster. The second issue is lubrication will leak out through the opened up seam from the barreling effect.
Split Bush Problems:
- Lubrication loss through open seam
- Worse distortion under heavier loads
- Faster wear resulting in shorter service life
**Older inventory may still have split bushings until the remaining inventory is depleted and converted to solid bush. We anticipate all chains will be converted by mid 2023. #25 & Non-standard roller chains will still use split bushings.