Prepare the Test Information
Select the procedure used by your laboratory. Choose the material preset closest to the specimen. Confirm every suggested value against your controlled instructions.
Select a common test condition when useful. The preset fills ball and force values. You may change those values before calculation.
Enter the Primary Measurements
Enter the applied force and its unit. Enter the ball diameter and diameter unit. Record two perpendicular indentation measurements carefully.
The calculator averages both optical measurements. It calculates the Brinell hardness from that average. It also checks the indentation ratio automatically.
Review Geometry and Ovality
A suitable impression supports more reliable measurement. Very small impressions increase reading sensitivity. Very large impressions may indicate excessive loading.
The ovality calculation compares both measured diameters. A high difference can indicate surface problems. It can also indicate specimen movement or reading error.
Add Specimen Conditions
Record thickness, edge distance, and indentation spacing. Enter the surface condition and support method. These fields improve the test record.
The calculator provides configurable screening warnings. Those warnings are not formal compliance decisions. Final acceptance belongs to your approved procedure.
Analyze Repeated Tests
Add one row for each test location. Every row may use different force settings. Invalid geometry rows remain visible for review.
Valid rows feed the statistical summary. The tool calculates mean, median, and range. It also calculates sample deviation and variation percentage.
Estimate Measurement Uncertainty
Enter standard uncertainty for the force system. Add ball and optical measurement uncertainty. Enter the reference block contribution when available.
Batch repeatability enters the model automatically. The calculator combines independent components by root-sum-square. Expanded uncertainty uses the entered coverage factor.
Apply Acceptance Limits
Enter minimum and maximum hardness limits. You may also define a target and tolerance. The result receives a clear acceptance status.
Use uncertainty when your decision rule requires it. The simple status does not apply guard bands. Configure final decisions within your quality system.
Create the Test Record
Complete company, project, specimen, and operator fields. Record machine and calibration information. Add observations that affect interpretation.
Calculate before exporting the final report. Use CSV for spreadsheets and batch review. Use JSON for software integrations and archives.
Use Reverse Calculation Modes
Reverse indentation mode finds a required mean diameter. Enter force, ball diameter, and target hardness. The solver returns a mathematical indentation value.
Reverse force mode estimates the required applied force. Enter target hardness and the measured diameter. Verify the result against available machine settings.
Interpret Converted Values Carefully
Converted scales are only approximate estimates. Different alloys can follow different relationships. Heat treatment can change those relationships significantly.
Use approved conversion tables for contractual reporting. Use tensile estimates only for preliminary engineering review. Direct testing remains the preferred verification method.