GB/T 4340.2 is the Part 2 document in the GB/T 4340 Vickers hardness series, focused on verifying and calibrating Vickers hardness testing machines (including the force application system, indenter, and diagonal measurement system).
If you need help matching verification requirements to your tester type (bench, micro, or portable) and your lab’s calibration workflow, talk with our team before you schedule service or purchase accessories.
GB/T 4340.2-2025 — Metallic materials—Vickers hardness test—Part 2: Verification and calibration of testing machines
GB/T 4340.2 specifies how Vickers hardness testers are checked for compliance before they are relied upon for reportable Vickers hardness results under GB/T 4340.1. It covers both direct verification (checking key machine subsystems) and indirect verification (checking overall performance using reference blocks).
The active edition is GB/T 4340.2-2025 (published March 28, 2025; implemented October 1, 2025), replacing GB/T 4340.2-2012.
Quick Definition
GB/T 4340.2 is a verification and calibration standard for Vickers hardness testers and their measurement systems. It is used to confirm that a Vickers hardness machine is applying the intended test force and measuring indentation diagonals correctly, so Vickers hardness values are dependable.
What This Standard Covers
This part of the GB/T 4340 series addresses verification and calibration of the equipment used for Vickers hardness testing.
- Direct verification: Verification and calibration methods for the Vickers hardness tester, the Vickers indenter, and the diagonal measurement system.
- Indirect verification: Verification of the complete Vickers hardness tester using a Vickers hardness reference block (standard block).
- Applicability: Includes portable Vickers hardness testers, and clarifies that systems using different hardness-measurement principles (for example, ultrasonic impedance) are outside its scope.
Why This Standard Matters in Testing
Vickers hardness results depend on two core machine capabilities: accurate force application and accurate diagonal measurement. GB/T 4340.2 is the control point that ties those machine capabilities to a defined verification/calibration routine, which is often required for QA/QC release testing, internal calibration programs, and supplier/customer audit readiness.
When a test report, control plan, or customer purchase order cites GB/T 4340.1 for Vickers hardness testing, GB/T 4340.2 is commonly used to support the tester’s ongoing compliance through periodic verification and documented calibration records.
Common Materials, Product Types, or Applications Covered
GB/T 4340.2 is equipment-focused rather than material-specific. It is typically used anywhere Vickers hardness testing is performed on metallic materials, such as:
- Incoming inspection and heat-treat verification (case depth and microhardness traverses depend heavily on stable force and optics).
- Weld and HAZ evaluations where small indentations and repeatable measurement are important.
- R&D and failure analysis where hardness mapping and comparability across instruments matter.
Common Test or Verification Workflow
GB/T 4340.2 is most often used as part of a lab’s control cycle for hardness equipment.
Typical workflow: Confirm the tester is installed and functioning correctly, perform direct verification checks (including force-related checks and diagonal measurement system checks), and then perform indirect verification using a Vickers hardness reference block to verify overall performance. The outcome is documented in a verification report and/or calibration certificate aligned to the cited edition.
Practical caution: Verification requirements and tolerances can vary with the tester’s force range and configuration (for example, low-force and microforce work can be more sensitive to optics, vibration, and surface preparation influences). Match your verification setup to the force levels and scales you actually use.
Equipment Commonly Used for This Standard
GB/T 4340.2 points to an equipment-and-accessories path that supports both subsystem checks and system-level performance verification.
Common equipment: Vickers hardness tester (bench or portable), certified Vickers diamond indenter, diagonal measurement system (measuring microscope/optical system or image-based measurement), and certified Vickers hardness reference blocks for indirect verification.
Common verification accessories: Force verification instruments appropriate to the tester’s force range, tooling to support indenter checks, and stable fixturing/support to minimize shock and vibration during force application and measurement.
If you are configuring a new Vickers hardness station or upgrading optics, cameras, or calibration accessories to support GB/T 4340.2 documentation, you can request a detailed quote for a setup matched to your force range, throughput, and reporting needs.
How to Read This Designation or Revision
GB/T identifies a recommended (non-mandatory) national standard of the People’s Republic of China.
4340 is the Vickers hardness test series for metallic materials, and .2 indicates Part 2 of that series (verification and calibration of testing machines).
Revision sensitivity: When a contract or procedure cites “GB/T 4340.2,” confirm the exact year (for example, GB/T 4340.2-2025 vs. GB/T 4340.2-2012). Verification steps, acceptance limits, reporting content, and verification cycle expectations may depend on the cited edition.
Related Standards, Methods, or Frameworks
GB/T 4340.2 is intended to be used alongside the other parts of the GB/T 4340 series and supporting calibration references.
- GB/T 4340.1: Vickers hardness test method (where the hardness test procedure itself is defined).
- GB/T 4340.3: Calibration of Vickers hardness reference blocks used for indirect verification.
- GB/T 4340.4: Tables of hardness values (commonly used for conversions/lookup within the Vickers context).
- GB/T 13634: Calibration of force-proving instruments used for verification of uniaxial testing machines (often referenced when establishing traceable force verification capability).
Talk to us about GB/T 4340.2 equipment and verification planning
If you are aligning a Vickers hardness tester purchase, upgrade, or calibration plan to a GB/T 4340.2-2025 requirement, contact our team to discuss force range, optics/measurement configuration, reference blocks, and verification documentation needs.
