Half as thick as regular hex nuts, these nuts fit into spaces with low height clearances. They are about half as strong as medium-strength steel, and are often used for light duty applications, such as securing access panels. Also known as jam nuts, they can be threaded together to form a locknut that won’t move or loosen due to vibration. When fastening threaded rod, you can use two nuts to create a point for tightening the rod with a wrench. These nuts have less tensile strength than a standard hex nut when used alone.

Steel nuts are best for dry environments, since exposure to moisture and chemicals will cause them to rust.

The distinctive coloring on blue-dyed steel nuts makes them easy to distinguish from inch-size nuts.

Nuts that meet DIN 936 and ISO 4035 (formerly DIN 439B) adhere to international standards for dimensions and material composition to ensure compatibility with other products and tools. Although the DIN 936 and DIN 439B standards are no longer active, they are commonly referenced globally.

For technical drawings and 3-D models, click on a part number.