BoltCalc is a pre-calibrated offline utility tool designed for DIY enthusiasts, makers, and mechanics to identify thread sizes, verify drill bit compatibility, and estimate hardware weight without needing an internet connection.

Key Features Built Into the App:

1. Thread Pitch Gauge
• Instantly match physical bolts against standard Metric (0.50mm to 2.50mm) and Imperial (10 TPI to 32 TPI) thread sizes.
• Calibrate your screen's pixel-to-millimeter ratio against standard credit cards or custom values to ensure real-world accuracy.
• Displays commonly matched screw examples for each pitch.

2. Drill Bit Size Matching Table
• Search tap drill size reference charts for common Metric and Imperial fasteners.
• Displays exact tap drill dimensions alongside clearance fits (both close and loose tolerances).
• Copy dimensions directly to your clipboard or save references for quick offline lookup.

3. Live Unit Converter
• Swap measurements continuously between millimeters (mm), centimeters (cm), and decimal inches.
• Custom fraction composer converts decimal inputs to fractional representations down to 1/64".
• Quick-tap standard fraction list for rapid selections.

4. Material Weight Estimator
• Calculate hardware mass for plates, cylinder rods, hex bolts, and hex nuts.
• Computes weights based on manual dimension entries using standard material densities for Carbon Steel, Stainless Steel, Brass, Copper, Iron, and Aluminum.
• Displays estimates in both grams (g) and ounces (oz).

5. Project Hardware Counters
• Manage tallies for custom hardware categories (e.g. M6 Washers, 10-24 Screws).
• Keep counts on how many fasteners you need to purchase or check out.
• Reset or remove counters instantly.

6. Local Saved References
• Keep a bookmark list of frequently referenced drill bit matches, material weight estimates, and unit conversions.
• Completely searchable and filterable.

Privacy & Offline Commitment:
• 100% Offline: Runs locally on your device CPU. No internet connection or cellular signal is required.
• Zero Data Collection: We collect no analytics, user statistics, or crash reports. Your calculations and saved references remain entirely private to your device.