Glossary

ISO is the International Organization for Standardization, a global, non-governmental body founded in 1947 and based in Geneva, Switzerland. It develops and publishes international standards to ensure quality, safety, efficiency, and worldwide compatibility across industries.

In the fastener industry, ISO standards specify dimensions, tolerances, material grades, finishes, and mechanical properties of bolts, nuts, washers, and screws. They often replace or harmonize older national standards such as DIN (Germany), BS (Britain), and ANSI/ASTM (United States), making fasteners interchangeable globally. For example, ISO 4017 defines requirements for a fully threaded hexagon head bolt, replacing DIN 933. Because ISO standards are recognized worldwide, they allow fasteners manufactured in one country to fit with components or tools from another, ensuring consistency in industries like aerospace, automotive, construction, and machinery.

In short, ISO guarantees that an ISO-designated fastener will meet the same specification anywhere in the world.