Conversion Charts
In the world of mechanical engineering, accuracy and efficiency are everything. Whether you’re designing precision components, fabricating metal parts, or working on-site with machinery, having the right conversion charts at your fingertips can save time, reduce mistakes, and improve workflow.
Useful Conversion Charts for Mechanical Engineers
Below are some of the most useful engineering charts and references every mechanical engineer should have bookmarked or printed — and yes, you can download them for quick offline access.
01. Drill and Tap Size Chart
The Drill and Tap Chart is one of the most frequently used references in machining and design. It helps you find the correct drill bit size for any thread tap, both metric and imperial.
Includes:
- Tap drill sizes for UNC, UNF, and metric threads
- Percent thread engagement
- Recommended tap drill formulas
02. Bolt and Nut Torque Chart
Proper torque ensures fasteners stay secure without breaking. This chart provides recommended torque values for various bolt sizes and grades.
Includes:
- Torque for SAE and metric bolts
- Lubricated vs. dry torque values
- Bolt grade strength references
03. Material Properties Chart
When selecting materials for strength, weight, or thermal resistance, a material properties chart is essential.
Includes:
- Yield and tensile strength
- Density and thermal conductivity
- Elastic modulus and Poisson’s ratio
04. Unit Conversion Chart
Mechanical engineers often switch between imperial and metric units. This conversion chart helps quickly convert between:
Includes:
- Length, mass, force, pressure, and energy units
- Temperature conversions (°C ↔ °F)
- Common mechanical unit relationships
05. Surface Finish Comparison Chart
Surface roughness can affect part performance and fit. This chart lets you compare Ra, RMS, and finish type values.
Includes:
- Surface roughness grades (N1–N12)
- Typical machining processes for each finish level
06. Fits and Tolerances Chart
Precision assembly depends on correct fits and tolerances. This chart helps you select the right interference or clearance fit.
Includes:
- ISO and ANSI fit designations (H7/g6, etc.)
- Recommended shaft and hole tolerances
07. Thread Pitch Conversion Chart
For quick reference between metric thread pitch and imperial threads per inch (TPI).
Includes:
- Common metric and UNC/UNF comparisons
- Drill size equivalents