ASTM B748 is a technical standard that defines a test method for measuring the thickness of metallic coatings by examining a cross section with a scanning electron microscope. It is used when precise coating thickness information is needed for inspection, quality control, or product verification. By focusing on cross-sectional measurement, the standard helps support consistent evaluation of coated parts where accurate dimensional data matters for performance and compliance.

What is ASTM B748?

ASTM B748 is the Standard Test Method for Measurement of Thickness of Metallic Coatings by Measurement of Cross Section with a Scanning Electron Microscope. It describes a measurement approach based on viewing the coating and substrate in cross section, allowing thickness to be assessed with microscopic detail. This makes it a useful ASTM standard for technical evaluation where coating buildup must be checked carefully and repeatably. ASTM B748 is especially relevant when visual inspection alone is not sufficient.

Where is ASTM B748 used?

ASTM B748 is commonly used in laboratories, inspection departments, and manufacturing quality control workflows that evaluate metallic-coated components. It may be applied to plated or otherwise coated parts when cross-sectional thickness verification is required. The method is also useful in failure analysis, incoming inspection, and process validation, particularly when a scanning electron microscope is already part of the testing setup. ASTM B748 supports measurement work that depends on detailed sectioning and microscopic observation.

Why is ASTM B748 important?

This standard helps promote consistent thickness measurement for metallic coatings, which can be important for product acceptance and process control. ASTM B748 gives engineers and inspectors a defined method that supports more reliable comparisons between parts, lots, or suppliers. That consistency can reduce disputes, improve documentation, and strengthen confidence in coating performance. For organizations that depend on accurate test results, using ASTM B748 can help align measurement practices with a recognized technical procedure.

• Cross-sectional measurement of metallic coatings
• Scanning electron microscope-based evaluation
• Quality control and inspection support
• Coating thickness verification for technical documentation