ThreadSpec Pro : Thread Calc

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Everyone
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About this app

ThreadSpec Pro is a thread calculator for machinists, CNC programmers, manufacturing engineers, and inspectors.

Look up common unified and metric sizes from reference tables, or calculate specials with ASME B1.1 and ISO 965-1 tolerance formulas. Cut tap and form tap drill sizes in results. Built with speed and time-saving in mind. Instant results.

WHAT IT DOES:

• CNC thread calculator
• Unified: UNC, UNF, UN, UNEF
• Controlled root: UNJ / MJ
• Metric coarse, fine and extra fine
• External and internal classes
• Plating range with pre-plate limits
• Thread height, lead, helix, single/double depth
• Cut tap and form tap drill sizes on internal threads up to 1.500" and 36 mm
• Recommended RPM calculation using material SFM, tool, and thread size
• Job number, part number, and heat-lot fields
• Save, print or share PDF report
• History saved (PDF, PRINT, SHARE)



SOURCE LABELS
TABLE means the size was taken from the in-app reference table.
CALCULATED means the size used the published tolerance formulas. Official tables still win when you are inspecting a part.

HOW TO USE IT
Pick series, class, and a common size, or type a special diameter and pitch. Add the plating min/max when the print calls for coating. Thread limits will be calculated accordingly. Send the report to the traveler.

IMPORTANT
ThreadSpec Pro is a shop helper. It is not a certified gage and not a substitute for ASME, ISO, the customer print, or your inspection department. Verify critical values before you cut or accept a part.

From Quantum Coding.
Precision thread calculator for Unified, UNJ, Metric, and MJ. Tap Drill sizes.
Updated on
Oct 13, 2026

Data safety

Safety starts with understanding how developers collect and share your data. Data privacy and security practices may vary based on your use, region, and age. The developer provided this information and may update it over time.
  • No data shared with third parties
    Learn more about how developers declare sharing
  • No data collected
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What’s new

What's new
• Internal threads now show Cut Tap Drill (75%) and Form Tap Drill
• Form tap is the larger hole: major minus half the pitch
• Both callouts follow the inch / mm switch
• Shown through 1-1/2 in. and 36 mm
Content rating
Everyone
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App support

About the developer
GEORGE ARTELIO SCARFO
support@quantumcoding.app
12 Ayer Cir Seabrook, NH 03874-4001 United States