The Ultimate Guide to Roller Chain Sprockets

From conveyors to agricultural machinery and printing presses, roller chain sprockets are one of the driving forces, so to speak, of the industrial world. Selecting the appropriate sprocket type, size, and dimensions for your application is not only vital to maximum uptime, but also to maintaining and improving efficiency.

Roller Chain Sprocket Dimensions

Finish Bore Roller Sprocket Sprocket DimensionsWhile dimensions such as the outside diameter, length-thru-bore (LTB), and hub diameter vary widely, the most searched-for characteristics are the sprocket bore size, chain size, and number of teeth.

Bore Size

The bore of the sprocket is the inside diameter of the sprocket through which the drive shaft is secured. Here at MDS, we carry sprockets with bore sizes ranging from ½” to 2”, depending on the type.

Chain Size

The size of the roller chain that will be used is important in determining the appropriate sprocket because chain size – regularly displayed as an ANSI standard chain number such as #35 chain and #40 chain – references the pitch of the chain. The pitch of the chain is the distance between roller centers (pins).

For example, popular chain sizes such as #35 chain and #40 chain equate to 3/8” pitch and ½” pitch, respectively.

Number of Teeth

The number of teeth on a roller chain sprocket is a relatively straightforward characteristic. It is often used in place of caliper diameter as a point of reference. In fact, if the teeth are worn away, the caliper diameter can be used to determine how many there were when selecting a replacement.

Roller Chain Sprocket Types

Idler Sprockets

An idler sprocket is unique in a couple of ways. First, it is not used as a drive sprocket or driven sprocket. Rather, it is typically placed in between the two and used to control and maintain tension in the chain.

Second, idler sprockets feature built-in ball bearings which allow them to spin freely from the drive shaft. The ball bearings are typically self-lubricated.

Finished Bore Roller Chain SprocketFinished Bore Sprockets

When the bore of a sprocket is machined for a specific drive shaft diameter and also includes keyways and set screws, it is referred to as a finished bore sprocket.

QD Bushed Sprockets

The primary benefit of Quick Detachable roller chain sprockets is their ease of use and high torque capacity. They feature bolt holes that allow them to be secured to bushings.

Taper-Lock Sprockets

Used with taper-lock bushings, taper-lock sprockets are useful for their versatility. The bore of the bushing tapers, allowing it to slide into a snug fit on the drive shaft. The bushing fits inside the taper-lock sprocket and is secured with set screws.

Just as there is a wide variety of industrial machinery, there is a wide selection of roller chain sprockets. For help finding the one you need, request information from the professionals at MDS.

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