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True as Steel

Measurement science for the nation’s most critical structures

MML Measures Up logo on background of hexagons

NIST helps to ensure the quality of steel, one of the most widely traded commodities on the planet.

The Material Measurement Lab at NIST makes certified reference materials for steel composition, hardness, and toughness that help producers control quality and performance aspects during manufacturing, and give buyers confidence that products meet their specifications.

Hundreds of varieties of steel are used for applications as small as surgical tools and as large as sky scrapers. Since the chemical composition helps to ensure the characteristics of the final products, providing corrosion resistance to clamps and scalpels or high strength to pipelines, we make reference materials that manufacturers use to check instruments for the chemical analysis of alloys.


Charpy Machine
The Charpy impact test uses a swinging pendulum to assess the resistance of a material to fracture. 
Credit: Geoffrey Wheeler

Where failure is not an option—as for bridges, pressure vessels, and nuclear power plants—steel producers and buyers want reassurances about strength. Tests for hardness are the most common methods manufacturers use to assess the strength of materials. Differences in test results can lead buyers to reject materials that are in fact suitable or, even worse, accept materials that are deficient. We produce and certify a variety of reference materials for calibrating hardness testing machines.

For testing toughness, the $10 billion-a-year structural steel industry relies on the NIST Charpy Machine Verification Program, which both produces and certifies specimens for use in impact test machines, and works directly with over 1,500 test labs per year to diagnose problems that may arise during verification testing.

We also participate in and provide leadership to ASTM and ISO committees, sharing our expertise, research, and experience with the community. Testing based on certified reference values and standards provides a common language for manufacturing, buying, and selling steel.

>130 million tons of steel are qualified each year with test machines traceable to NIST
>1,500 customers each year depend on NIST for testing the toughness of steel
7,000 copies of the NIST Recommended Practice Guide on Rockwell Hardness Measurement have been requested. Rockwell is just one of the many hardness tests we support

Released April 9, 2018, Updated July 19, 2022