CNC Thread & Fit Calculator

About CNC Thread & Fit Calculator

CNC Thread & Tolerance Generator – Professional CNC Calculator

The CNC Thread & Tolerance Generator is a fast, accurate, and reliable tolerance calculator designed specifically for CNC machinists, programmers, turners, millers, and quality inspectors. Forget flipping through thick reference books and calculating by hand next to the machine – get all the vital data in one place, instantly.

Since time is money in the workshop, the app is clean and to the point. It combines ISO and ASME fits, metric and imperial threads, smart reverse engineering, as well as surface roughness and hardness calculations into one smart interface.

KEY FEATURES:

• ISO & ASME Fits — Full support for hole and shaft fits (ISO 286-1 mm, ASME B4.1 inch).
• Comprehensive Thread Calculator — Complete database for Metric (M1–M150, coarse/fine pitches, 6G/6h/6e tolerances), Imperial (UNC, UNF, UNEF), G/BSPP (ISO 228-1 external A/B tolerances), Trapezoidal, and R (tapered) threads.
• General Tolerances — Quick linear, form, and position tolerance calculations according to ISO 2768 (f, m, c, v).
• Smart "Reverse" Search — Enter custom drawing tolerances (e.g., +0.05 / 0), and the app instantly finds the closest standard fit (e.g., H7, G9).
• Mid-Tolerance Calculation — Highlighted in every mode, saving you massive amounts of time when entering tool wear offsets during CNC programming.
• MM / INCH Toggle — Seamless, real-time conversion between metric and imperial units.
• Surface & Hardness Module — Tool radius-based theoretical roughness calculation, Ra–Rz–Rt ISO slider (N1-N12 + DIN 3141 machining symbols), and a highly precise hardness converter (HV, HB, HRC, Rm).
• Smart User Interface — Only standards-compliant pitches and tolerances are shown. Clean, dark-mode design optimized for the workshop environment.

FREE VERSION (with 14-Day PRO Trial)
For the first 14 days after downloading, the entire PRO database (all extended tolerances and thread classes) is fully unlocked to try, alongside basic ad displays. After the trial period expires, the core ISO and thread tolerance zones will remain completely free to use.

PRO VERSION (One-Time In-App Purchase)
Support the development and enjoy unlimited work with no monthly fees!
• Unlock the Full Database Forever: Gain permanent access to all rare ISO fits, special thread classes, and the complete ASME database.
• 100% Ad-Free Experience: A smooth, distraction-free working environment next to the controller.
• Lifetime License: Buy it once, own it forever. No subscriptions.

Make your daily work faster and more accurate with the most advanced CNC tolerance calculator!