Thread Chart: Tap Drill & CNC

Siberian Apps

Contains ads

About this app

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.

Ratings and reviews

Works great and tons of info. One more star if updates get made to go one step above everyone else in this space.. would be fantastic if the calculations that are auto generated are also applied to to the thread profile image. For the moment we still get the typical image with formulas (5h/8, p/8, etc), why not let the app do the rest of the calculations.. would gladly purchase a pro version if such a tool were available.

I use this app at work mostly to figure out ID and OD for machining threads. So far it's worked great. I can't tell on the rest of the app as I haven't explored or needed the rest of it.

Like the update. Very useful at work. 5 stars. I Would like to see the hole size needed for the chosen thread make a return.

What’s new

• Redesigned thread identifier: units (mm/inch), thread
type (internal/external), quick examples
• Fixed the root fillet radius in Whitworth
(BSW/BSF/RC) profiles
• Fixed the root chamfer width in ACME Stub threads
• You can now turn off ads for 8 hours by watching one
short video