What is the requirement for the supporting surface on which specimens are stored?

The requirement for the supporting surface on which specimens are stored is that it must be level within 1/4 inch. This standard ensures that specimens are not subjected to undue stress or distortion, which could affect their integrity and the results of any testing performed on them. A level surface minimizes variations in the placement of specimens, thus reducing the risk of errors in measurements and ensuring that data collected during testing is both accurate and reliable.

When specimens are stored on an uneven surface, it can lead to issues such as warping, bending, or other forms of degradation. Therefore, maintaining a strict tolerance of 1/4 inch provides a balance between practical storage conditions and the precision necessary for scientific analysis. Ensuring the surface is within this specified level helps establish good practice in sample handling and preparation, which is critical in adhering to ASTM standards and achieving valid and repeatable results in materials testing.