# DatumCalc

Free CNC and machinist calculators: feeds and speeds, chip load, tap drill, thread pitch and more, with the formula shown and the cutting data sourced.

## Calculators
- /bolt-circle-calculator/                Bolt Circle Calculator
- /chip-load-calculator/                  Chip Load Calculator
- /countersink-depth-calculator/          Countersink Depth Calculator
- /dovetail-calculator/                   Dovetail Measurement Calculator
- /drilling-feeds-and-speeds-calculator/  Drilling Feeds and Speeds Calculator
- /feeds-and-speeds-calculator/           Feeds and Speeds Calculator
- /form-tap-drill-calculator/             Form Tap Drill Size Calculator
- /fraction-decimal-mm-converter/         Fraction to Decimal to MM Converter
- /gear-ratio-calculator/                 Gear Ratio Calculator
- /hardness-conversion-calculator/        Hardness Conversion Calculator
- /knurling-calculator/                   Knurling Diameter Calculator
- /machining-cost-calculator/             Machining Cost Calculator
- /material-removal-rate-calculator/      Material Removal Rate Calculator
- /metal-weight-calculator/               Metal Weight Calculator
- /sine-bar-calculator/                   Sine Bar Calculator
- /single-point-threading-calculator/     Single-Point Threading Calculator
- /spindle-power-calculator/              Spindle Power Calculator
- /steps-per-inch-calculator/             Steps Per Inch Calculator
- /surface-finish-calculator/             Surface Finish Calculator
- /surface-speed-calculator/              Surface Speed Calculator
- /tap-drill-size-calculator/             Tap Drill Size Calculator
- /thread-data-calculator/                Thread Dimension Calculator
- /thread-milling-calculator/             Thread Milling Feed Calculator
- /thread-pitch-calculator/               Thread Pitch Calculator
- /trig-calculator/                       Right Triangle Calculator
- /true-position-calculator/              True Position Calculator
- /turning-feeds-and-speeds-calculator/   Turning Feeds and Speeds Calculator

## Reference
- /cutting-data/      - starting surface speeds (SFM) and chip loads by material, with sources
- /drill-size-chart/  - fractional, number and letter drill sizes in decimal inches and mm
- /about/             - sources and method

## Notes
Recommended speeds and feeds are published starting values that depend on machine rigidity, tool
brand and coating, workholding and coolant. They are starting points, not limits or guarantees.