GB/T 2490-2018 in English

Analysis of the core content of the standard

Detailed explanation of technical points

Sandblasting hardness test

Adopt quartz sand blasting method, key control points include:

• Nozzle distance: 9.0±1.0mm
• Sand chamber volume: 5cm³ (FL grade) or 28cm³ (MY grade)
• Correction of glass pit depth: 5cm³ sand chamber 0.53±0.03mm

Rockwell hardness test

Differentiated parameters are used for different particle sizes:

Recommendations for implementation of the standard

1. Establish a regular equipment calibration system, especially the pressure gauge accuracy must be maintained above level 1.6
2. For large-sized abrasive tools (diameter＞1000mm), it is recommended to make process samples for testing
3. When judging the hardness uniformity, the difference between the two points of the sandblasting method should be ≤30% of the grade difference

Technology Evolution Analysis

Compared with the 2007 version, the main improvements of this standard are reflected in:

• Added 35/36/37 grinding wheel working surface inspection regulations
• Chemical composition requirements for refined quartz sand (SiO₂≥95%)
• Clearly control the test force application time (1-8 seconds)