F.A.Q.
What Is a Hardness Test Block?
A hardness test block is a certified reference specimen used to verify the performance and accuracy of a hardness testing machine. Each block has a defined hardness value established through a controlled calibration process and documented in a certificate traceable to recognized international standards.
Certified hardness test blocks are used for routine checks, calibration procedures, machine verification after maintenance or relocation, and whenever traceable hardness results are required by internal quality systems or customer specifications.
When Is a Hardness Test Block Used?
Hardness test blocks are used:
- Before daily use of a hardness tester (as part of routine verification)
- During periodic calibrations by accredited laboratories
- After repairs or mechanical adjustments
- To ensure test consistency across different operators or machines
They are essential for confirming that your Rockwell, Brinell, Vickers, or Knoop hardness tester is providing accurate and repeatable results.
When Is It Necessary to Use a Certified Block?
A certified test block is typically required when:
- You must comply with ISO/IEC 17025, ISO, or ASTM quality standards
- You are performing internal audits or external inspections
- Your process requires traceable results (e.g. aerospace, automotive, or medical industries)
- Your hardness tester has not been verified recently or has been moved or adjusted
How to Maintain a Hardness Test Block
To ensure the accuracy and longevity of your test blocks:
- Avoid repeated testing on the same area; use the entire surface systematically
- Store in a protective case, away from dust and humidity
- Clean regularly with alcohol or a lint-free cloth
- Avoid contamination or oil residue from samples
- Replace when surface wear or deformation is visible
- Recalibrate annually, or as required by your internal quality procedures