Thread Chart: Tap Drill & CNC

The thread chart and tap drill reference you actually want on the shop floor. Every thread standard, machining calculator and thread identifier in your pocket — ready in seconds, no internet required.

Machinists, CNC programmers and engineers use it daily: to identify an unknown thread by caliper measurement, look up tap drill sizes, calculate speeds and feeds, and reference specs across 28 thread standards — all without leaving the machine.

THREAD CHART & TAP DRILL CHART
Look up any thread size chart entry: pitch, TPI, major and minor diameter, tapping drill, clearance drill and more — and find the right drill bit size for any tap. Metric, UNC, UNF, UNEF, UNS, UN, BSW, BSF, BSPP, BSPT, NPT, NPTF, RC, ACME, Stub ACME, Trapezoidal, Buttress, Knuckle, Worm, API, PG, British, metric conical, conical inch, conical lock and pipe conical threads — all in one place.

THREAD IDENTIFIER BY MEASUREMENT
Got an unknown thread? Measure with calipers, enter the diameter and pitch or TPI — the app instantly matches it across every supported standard.

THREAD PROFILE DIAGRAMS
Clear diagrams for each thread type — see the geometry, understand the form, spot the differences between standards at a glance.

SPEEDS AND FEEDS CALCULATORS
Cutting speed (SFM), spindle speed (RPM), feed rate (IPM), feed per tooth (chip load), feed per revolution, machining time, material removal rate, cutting power, cutting torque and depth of cut — for lathe turning, milling and general workshop setup.

THREAD MEASUREMENT
Three-wire method: pitch diameter calculation and best wire size for any thread, plus a metric thread calculator with full profile dimensions.

FITS & TOLERANCES
ISO fits calculator for any shaft and hole combination (H7/g6 and more), tolerance tables, general tolerances ISO 2768, surface roughness Ra/Rz and bearing fits.

GEOMETRY CALCULATORS
Cone dimensions, hex and square blanks, coordinate rotation, trigonometry and degree conversions.

MACHINE SHOP CONNECTIONS
Keyway, spline and eccentric connection calculations.

REFERENCE TABLES
Hardness conversion (Rockwell, Brinell, Vickers), Morse taper chart, standard tapers, bolt torque chart, keyway dimensions, material density, melting temperatures, mechanical properties, thermal expansion, heat treatment of steels, solders and fluxes, cutting tool grades, cutter and drill grinding angles, cutting fluid, bearing designations and engineering drawing symbols.

WORKS OFFLINE
Every thread chart, table and calculator works without a connection. Built for workshops, production floors and lathe or CNC setup where Wi-Fi isn't always an option.

FAVORITES
Save the threads and calculators you use most for instant access.

Whether you're identifying a mystery thread, setting up a lathe or CNC job, calculating feeds and speeds, or you just need a tap drill size fast — it's one tap away.

Recent changes:
Fixed Morse taper data (small diameter) and cylindrical pipe
thread tolerances.