Roller chain sprocket wear teethTo a certain degree once a sprocket has worn it can cause rapid chain wear and will need to be replaced at the next available opportunity. However, replace it too early and you’ll be incurring unnecessary costs.

Here’s our guide to determining when a roller or conveyor chain sprocket needs to be replaced;

If you examine the faces of the sprocket teeth you should be able to tell immediately whether a sprocket has worn or not. You will notice a shiny strip on each of the teeth about the pitch circle diameter. The diagram below shows that a sprocket will need to be replaced if the depth of wear, dimension x, has reached 10% of dimension Y.

It is worth noting at this point that a high quality sprocket will have seen several chains before it shows anything like the extent of wear in the diagram. When sprockets are replaced it is essential that they are properly aligned with the shafts as misaligned sprockets are a common cause of premature chain wear. When shafts and sprocket tooth faces are accurately aligned, the load is distributed evenly across the entire chain width which helps to achieve maximum service life. A straight edge, nylon line or laser sight tool should be used across the machined faces of the sprockets in several positions to check for wobble. When sprockets have been correctly aligned, you should drive the keys home as a final check.

Sprocket tooth wear can also occur when low grades of sprocket material have been utilised, or when using small sprockets with a speed ratio greater than 4:1.

It is often appropriate to manufacture the sprockets with hardened teeth to overcome some of the issues associated with escalating tooth wear.

FB has the engineering capability to offer sprockets in materials to suit the application conditions such as special grade alloy steels.

Another FB Chain speciality is the ability to manufacture high quality sprocket segments in order to offer split sprocket solutions, saving large amounts of down time when replacing large difficult to access drives.