ASTM D938

ASTM D938 is the ASTM standard for determining the congealing point of petroleum waxes, including petrolatum. It provides a consistent way to assess the temperature at which these materials begin to lose fluidity and set, which is useful for comparing product behavior and supporting quality control. For manufacturers, buyers, and testing laboratories, this standard helps bring clarity to a property that can affect handling, storage, and product performance.

Overview of ASTM D938

The Standard Test Method for Congealing Point of Petroleum Waxes, Including Petrolatum is used to measure a key thermal characteristic of waxy petroleum materials. In practical terms, it helps define the point at which a sample begins to congeal under controlled test conditions. ASTM D938 is commonly used where consistent material characterization is needed for specification compliance, product evaluation, or batch-to-batch comparison. As a technical document, it supports repeatable testing and more reliable communication between suppliers and end users.

Common use cases of ASTM D938

This standard is commonly used in testing petroleum waxes and petrolatum during production, incoming inspection, and final quality checks. It may be applied when a material specification calls for congealing point data or when comparing lots from different sources. Laboratories and quality teams often rely on ASTM D938 to support release decisions, document performance trends, and confirm that wax-based materials meet expected handling or processing requirements. It is especially useful wherever congealing behavior is part of product acceptance.

Benefits of using ASTM D938

Using ASTM D938 helps create a common basis for evaluating congealing point results across suppliers, laboratories, and internal quality systems. That consistency can reduce ambiguity in procurement and improve confidence in product comparisons. The standard also supports better traceability in testing records and can help limit risk when congealing behavior affects storage, processing, or end-use suitability. For organizations managing petroleum waxes or petrolatum, ASTM D938 is a practical tool for compliance and quality control.

• Measures congealing point for petroleum waxes and petrolatum
• Supports repeatable laboratory testing
• Useful for quality control and product comparison
• Helps align procurement and specification requirements
• Provides a standard reference for material evaluation