Hexmuttern

Hexmuttern, or hex nuts, are hexagonal threaded fasteners designed to mate with a corresponding bolt or screw. The six flat sides provide multiple wrenching points for tightening and loosening. The internal thread is sized to match a bolt diameter, and practical engagement depends on thread pitch and length of engagement.

They are among the most common fasteners in mechanical assemblies and are manufactured in various materials and grades to suit loads, temperatures, and environments. Metric hex nuts typically follow ISO or DIN standards (for example ISO 4032) and come in coarse and fine thread forms, while inch-series versions follow ANSI/ASME standards.

Materials include carbon steel, stainless steel, alloy steel, brass, and sometimes corrosion-resistant coatings. Common finishes include zinc plating, hot-dip galvanizing, black oxide, blue zinc, and passivation for stainless steel.

Variants of hex nuts include flange hex nuts, serrated edge hex nuts, and nylon-insert lock nuts (nylock) that resist loosening due to vibration. There are also special-purpose hex nuts with mounting features or self-locking properties.

In use, hex nuts require compatible bolt threads and, depending on the material and grade, appropriate torque is specified to avoid over-tightening or thread damage. The length of thread engagement and hardware compatibility influence load transfer and joint integrity. Proper selection and installation are essential for reliable fastening.