ASTM C729 is the ASTM standard titled Standard Test Method for Density of Glass by the Sink-Float Comparator. It provides a technical basis for determining glass density using a sink-float comparator method, helping users compare and evaluate glass materials in a controlled way. This matters for quality control, material verification, and product consistency where density is an important property. As an ASTM document, it supports more reliable testing and clearer communication between suppliers, laboratories, and buyers.

What is ASTM C729?

ASTM C729 defines a standard test method for measuring the density of glass by the sink-float comparator. In practical terms, it describes a controlled approach for comparing a glass specimen against liquids or reference conditions so its density can be assessed consistently. The standard is useful when laboratories need a repeatable method tied to a recognized ASTM framework. ASTM C729 helps support uniform test practices and more dependable results when density is part of a material evaluation program.

Where is ASTM C729 used?

This standard is commonly used in glass testing environments where density measurement is needed for inspection, research, or production control. It is relevant in laboratories handling glass products, materials development workflows, and quality assurance programs that rely on standardized comparison methods. ASTM C729 may also be used when verifying material identity or checking consistency across batches. Because it focuses on a specific measurement method, it fits well into technical operations that require repeatable glass property testing.

Why is ASTM C729 important?

ASTM C729 is important because it gives users a recognized test method for evaluating glass density in a consistent way. That consistency supports compliance, procurement decisions, and internal quality control by reducing uncertainty in test results. When glass properties need to be compared across suppliers, lots, or laboratories, a standard method helps improve confidence in the data. It can also reduce testing risk by providing a clear procedural reference for the sink-float comparator approach.

• Standard test method for glass density
• Sink-float comparator approach
• Quality control and verification use
• Supports repeatable laboratory testing
• Useful for material comparison and evaluation