If you find a chisel that has a mushroomed head, what should you do?

When a chisel has a mushroomed head, it indicates that the top of the chisel has been deformed, typically from repeated striking with a hammer. This deformation can cause the chisel to become less effective and can pose safety risks when using the tool. Grinding the head down to its proper shape is the best approach because it restores the chisel to its original functionality.

By properly shaping the head, you ensure that the chisel can be effectively used for its intended purpose without compromising the user's safety. Additionally, it enhances the precision and control when applying force, which is critical in maintenance tasks.

Using the chisel as is could lead to hazardous situations such as the head chipping off during use, which can cause injuries. Replacing it might also be unnecessary if restoring its shape can maximize its lifespan and utility. Filing down could be a partial solution, but grinding is more effective for restoring the chisel to a proper working state.