How much scrap material is recommended for checking the countersink tool?

The recommended amount of scrap material for checking the countersink tool is 10 to 12 holes. This range is practical because it allows for a sufficient number of test holes to ensure the tool is performing accurately and consistently. By checking this many holes, a mechanic can identify any inconsistencies in the countersink or any wear that might affect the quality of the hole being produced.

Using fewer holes might not provide an adequate assessment of the tool’s performance, as variations can occur from hole to hole. Conversely, utilizing significantly more than 12 holes could lead to unnecessary use of material and time, which could be better spent on productive tasks. Therefore, 10 to 12 holes strikes a balance between efficiency and thoroughness in checking the tool's effectiveness.