Why tooling cost per part matters
Insert and tool cost rarely gets factored into a quote as carefully as material and machine time, yet on aluminum finishing passes or hard-material roughing it can be one of the larger line items in the true cost of a part. A single insert edge that only lasts 150 parts contributes real dollars to every one of those parts, and that number needs to be part of the quote, not an afterthought absorbed into overhead.
How the numbers are calculated
Tooling cost per part equals the tool or insert price divided by the tool life in parts per edge, multiplied by the number of usable edges per tool. An indexable insert with four usable edges effectively quadruples the parts you get out of a single insert price, so tracking edges rather than just tools is what makes this number accurate.
Practical tips
Tool life numbers from a catalog are a starting point, not gospel. Track actual parts per edge on your own machines and materials, since feed rate, coolant, and material hardness all shift real tool life away from published figures. Revisit this number whenever a job moves to a harder material or a more aggressive feed strategy, since tooling cost per part can change more than material cost does between similar-looking jobs.