Black Carbon Steel Thin Hex Nuts

Tighten these metric nuts to the left to make them resist loosening from counterclockwise motion. They’re made of Class 04 steel, so they’re suitable for fastening most machinery and equipment. Also known as jam nuts, they’re about half the height of standard hex nuts. Use them in low-clearance applications or jam one against another nut to hold it in place. When used alone, they have less tensile strength than standard hex nuts. A black-oxide finish gives them a dark surface color and makes them mildly corrosion resistant in dry environments.

These nuts meet ISO 4035 (formerly DIN 439B), so their edges are chamfered and are less sharp than DIN 936 nuts. This new ISO standard is functionally the same as the DIN standard it replaced, with slightly different tolerances for width.