What’s That Tolerance Costing You?

For design engineers, this new tool

Answers “am I being paranoid or reasonable?” in five seconds. An engineer types in a feature, material, size, and target tolerance, and gets an immediate verdict: Routine, adds cost, needs a special process, or beyond what’s practical. That judgment normally lives in a senior machinist’s head, and a designer only gets it after sending a drawing out. The tool front-loads it.

Translates a tolerance into the process it actually implies. Because the engine runs on ISO 286 grades, it can say a given callout is roughly IT6 on a bore, which means fine boring or grinding rather than a standard turning pass. That’s the exact translation that tells an engineer whether they’ve quietly committed the shop to a secondary operation.

Shows the cost of holding a tolerance versus relaxing it. Cost climbs steeply as tolerances tighten, and that curve isn’t intuitive. The tool gives a relative-cost figure and, more usefully, a recommended “free” tolerance for that feature — so an engineer can see that opening a dimension from ±0.0002″ to ±0.001″ drops it out of grinding territory without hurting the fit. That’s the over-tolerancing money most drawings leave on the table.

Catches issues when the material, not the machine, is the limit. The genuinely useful edge case: it flags when a tolerance is fighting physics rather than shop capability. For example, ssking a plastic part to hold a sub-thou dimension it can’t keep through thermal expansion, or a titanium feature that will spring back. That’s a mistake a designer can otherwise carry all the way to first article.

The Tolerance Checker Tool makes manufacturability legible before the drawing is released. It turns the tolerance block from a habit (defaulting to tight because tight feels safe)  into an informed decision, and it lets an engineer distinguish the tolerances that genuinely matter for function from the ones that are just quietly adding cost and lead time.