Clearance Hole Calculator Pro (USA)
Calculate precise drill bit sizes for US Customary Screws based on ASME B18.2.8 standards.
Visual Cross-Section (Not to scale)
Clearance Hole Dia
0.000″
Inches
Recommended Drill
—
Fractional
How to Use This Calculator
Using the Clearance Hole Calculator Pro (USA) is simple. Select your screw size (from #0 up to 1 inch) and choose the desired fit type. The tool instantly provides the exact hole diameter and the standard drill bit required.
Understanding Hole Fit Types
According to engineering standards (ASME B18.2.8), there are three primary categories for clearance holes:
- Normal Fit: The most common choice for general assembly. It allows for easy assembly while providing adequate alignment.
- Close Fit: Used for precise alignment where minimal lateral movement is desired. Assembly may be slightly more difficult.
- Loose Fit: Used where adjustment or movement between parts is necessary, or for painting/plating thickness variations.
Disclaimer: Always verify measurements with a caliper before drilling critical materials. Values are based on standard inch charts.
