ANSI Fit & Thread

🚀 Speed up your engineering designs and machining setups! ANSI Fit & Thread is an offline, precision calculator tailored for mechanical engineers, CNC operators, machinists, designers, and students.

Calculate standard tolerances, clearance/interference limits, thread geometries, and tap drill sizes instantly using imperial ANSI standards.

Key Features:

1. ANSI B4.1 Fits & Tolerances Calculator

• Enter nominal sizes (from 0.01" up to 19.69") and get exact limit values.

• Supports standard ANSI tolerance classes including:

- Running/Sliding Fits (RC)

- Locational Clearance Fits (LC)

- Transitional Fits (LT)

- Locational Interference Fits (LN)

- Force/Shrink Fits (FN)

• High-fidelity engineering diagrams showing hole/shaft envelopes.

• Displays Max/Min clearances, interferences, and Allowance.

2. Unified Thread Pitch Calculator

• Look up standard ANSI/ASME thread details (UNC, UNF series).

• Instantly retrieves Major Diameter, TPI (Threads Per Inch), Pitch, Pitch Diameter, and Minor Diameter.

• Shaded 60° thread profile visual diagrams showing reference boundaries.

3. Tap Drill Size Calculator

• Instantly calculates the theoretical ideal tap drill size.

• Recommends the best standard drill bits (Fractional, Letter, Number, or Metric sizes) for target thread engagements.

• Displays real-time thread engagement percentage progress charts.

• Provides alternative drill sizes with precise decimal equivalents.

• Tapped hole engineering cross-hatch diagrams with clear annotations.

4. History Management & Export

• Auto-saves recent calculation records to a rolling history list.

• Pin favorite measurements so they never expire.

• Search through history by custom names, sizes, or parameters.

• Export history to a standard CSV file for spreadsheets and reports.

• Native Android share sheet support with clean diagram images and text descriptions.

Why Choose ANSI Fit & Thread?

• 100% Offline: No internet connection required. Perfect for workshops and factories.

• Privacy First: Zero accounts, zero analytics tracking on calculation details. Your data stays on your device.

• Single-Screen UX: Smooth tab navigation with clear, readable monospaced layouts—no nested menus or popups.

• Clean M3 Design: Optimized light and dark themes with Machinist Steel styling.

Disclaimer: This application is a curated lookup and formula reference tool. For safety-critical or production tolerancing designs, always cross-reference outputs with official ANSI/ASME standards.