About the Data

A reference site owes you a straight answer about where its numbers come from. Here's ours.

Computed, not copied

Thread dimensions, tap drills, speeds-and-feeds math, chip thinning, effective diameters — all of it is computed from published, standard engineering formulas (the same math behind ASME B1.1, ISO 965, and the formulas printed in every machining text). Formulas aren't copyrightable; the specific tables printed in standards documents are. So we run the math ourselves and verify the output against a set of known spot values, with automated tests that run before anything ships.

Facts, aggregated

A drill size's decimal equivalent, a material's density, a designation like CNMG or M6×1 — these are facts, and facts belong to everyone. Our cutting-data starting points are an original aggregation of general shop consensus across many years and many sources, deliberately conservative, in our own structure. Nothing is mirrored from any standard, handbook, or manufacturer's catalog.

Approximations are labeled

Some useful numbers are inherently approximate — hardness scale conversions, tensile-from-hardness estimates, machinability ratings, theoretical surface finish. Wherever a calculator shows one, it's labeled as an estimate in the interface. If a number isn't labeled, it's computed from the governing formula.

What this means for you

Starting points and reference values are exactly that. Machine rigidity, tooling, workholding, and coolant change everything; material certs override typical values; gauges and the governing standard override any calculator. Verify against certs and gauges before production use. If you find a value that looks wrong, tell us — corrections go to the front of the queue.