Vickers Hardness Number Calculator
Calculate Vickers hardness number from indentation measurements and applied force
Calculate Vickers Hardness Number
Force applied by the diamond indenter
Average of the two diagonal measurements
Standard diamond indenter angle is 136° (pyramid angle)
Vickers Hardness Results
Test Parameters
Applied Force: 0.0 N (0.00 kgf)
Mean Diagonal: 0.000 mm
Indenter Angle: 136°
Indentation Area: 0.0000 mm²
Standard Notation
Complete Notation: 0HV0
Formula Used: HV = 2F·sin(α/2)/(g·d²)
Standard: BS EN ISO 6507-1
Test Duration: 10-15 seconds (typical)
Hardness Classification
Example Calculation
Steel Sample Test
Applied Force: 50 N (5.1 kgf)
Mean Diagonal: 0.5 mm
Indenter Angle: 136° (standard diamond pyramid)
Test Duration: 15 seconds
Step-by-Step Calculation
Step 1: HV = 2F·sin(α/2)/(g·d²)
Step 2: HV = 2 × 50 × sin(136°/2)/(9.80665 × 0.5²)
Step 3: HV = 100 × sin(68°)/(9.80665 × 0.25)
Step 4: HV = 100 × 0.9272/(2.4517)
Result: HV = 37.8 kgf/mm² ≈ 38 HV5
Vickers Test Procedure
Preparation
Polish specimen surface smooth and flat
Indentation
Apply specified force for 10-15 seconds
Measurement
Measure both diagonals and calculate mean
Calculation
Apply Vickers formula to get HV number
Typical HV Values
Test Standards
BS EN ISO 6507-1: Metallic materials
ASTM E384: Standard test method
Diamond pyramid indenter at 136°
Load application: 10-15 seconds
Force range: 1 gf to 120 kgf
Understanding Vickers Hardness Testing
What is Vickers Hardness?
The Vickers hardness test, developed in 1921, measures a material's resistance to plastic deformation. It uses a diamond pyramid indenter with a 136° angle to create a square-shaped indentation on the material surface.
Advantages of Vickers Test
- •Wide range of hardness values (soft to very hard materials)
- •Small indentation size for thin specimens
- •Independent of indenter size (unlike Brinell)
- •High precision and repeatability
Mathematical Foundation
HV = 2F·sin(α/2)/(g·d²)
H = HV × 9.80665/1000 GPa
σᵤ = H/c MPa
- HV: Vickers hardness number (kgf/mm²)
- F: Applied force (N)
- α: Indenter angle (136°)
- d: Mean diagonal length (mm)
- g: Gravitational acceleration (9.80665 m/s²)
- c: Material constant (≈3 for metals)
Test Considerations
Surface Preparation
Surface must be smooth, flat, and free from oxide layers. Proper polishing ensures accurate measurements.
Load Selection
Choose appropriate load based on material thickness and expected hardness. Common loads: 1, 5, 10, 30, 50 kgf.
Measurement Accuracy
Measure both diagonals to ±0.5% accuracy. Use optical microscopy for precise diagonal measurements.