When is it recommended to replace the moldboard or cutting edge?

The recommendation to replace the moldboard or cutting edge when it is 3/4" worn is based on maintaining the efficiency and effectiveness of the road grader. As the cutting edge wears down, its ability to cut and grade surfaces diminishes, which can lead to poorer performance and increased wear on other components of the machine.

When the cutting edge reaches 3/4" of wear, it typically has lost enough material that it may not effectively engage the soil or surface being graded. This level of wear can result in an uneven surface finish and longer grading times, as the machine will need to work harder to achieve the desired results.

While lesser degrees of wear might still allow the cutting edge to function, they do not account for the gradual decline in cutting efficiency that becomes evident at the 3/4" mark. Waiting until the cutting edge is worn down further could compromise the grading quality and contribute to additional wear on both the grader and the materials being graded, ultimately leading to more extensive maintenance needs or replacements in the long run. Thus, replacing it at 3/4" is a good balance between maintenance cost and operational efficiency.