# MachinistCharts

Free shop-floor reference for bolt torque and tap drill sizes, calculated from ISO 898-1, SAE J429, ASME B1.1 and ISO 273.

- Bolt torque chart: https://machinistcharts.com/bolt-torque/
- Tap drill chart: https://machinistcharts.com/tap-drill/
- Bolt torque calculator: https://machinistcharts.com/calculators/bolt-torque/
- Thread percentage calculator: https://machinistcharts.com/calculators/thread-percentage/
- Data: https://machinistcharts.com/data/bolt-torque.csv, https://machinistcharts.com/data/tap-drill.csv
- Guide for AI tools: https://machinistcharts.com/llms.txt

Source page: https://machinistcharts.com/
Updated: 2026-10-05
Publisher: MachinistCharts (https://machinistcharts.com)