UN & Metric Thread Geometry

UN & Metric Thread Geometry Calculator is a focused worksheet for nominal 60° external thread geometry. Enter metric major diameter and pitch, or UN major diameter and threads per inch, to see the fundamental height, pitch and minor diameters, best-wire size, and measurement over best wires.

Use the three-wire worksheet to enter a wire diameter and an over-wire measurement, then calculate the corresponding pitch diameter and its difference from the nominal result. Inputs, units, formula version, and assumptions stay visible alongside results. The free calculator and three-wire worksheet work without a PatchMedia account.

An optional one-time Pro purchase adds user-created saved cases, measurement notes, saved case comparisons, result CSV export, and user-directed JSON backup and import. Purchase availability and the local price are shown by Google Play. Existing saved cases remain readable and exportable if Play purchase status is temporarily unavailable.

Calculations run on your device. The app has no ads, PatchMedia analytics, account, or cloud synchronization. JSON and CSV files leave the app only when you choose a destination through Android. Exported files are not encrypted by the app.

Results use bounded user-entered values and basic 60° external formulas. The simplified three-wire equation omits helix-angle and wire-deformation corrections; use wires seated on both flanks above the crests. Results do not provide thread class, tolerance, fit, gage acceptance, inspection, manufacturing approval, or certification. Check the applicable engineering requirements before using a result in production.