11/16in LH Steel Jam Nut

The U-B Machine 11/16in Left-Hand Steel Jam Nut (Part No. 990-6818-2L) is a precision fastening component engineered for applications requiring secure, vibration-resistant locking in left-hand threaded assemblies. This jam nut features an 11/16-18 thread specification and is manufactured from steel with a zinc oxide finish, delivering corrosion resistance and reliable mechanical grip in demanding service conditions.

The left-hand thread configuration is critical for applications where standard right-hand threading would loosen under rotational forces or vibration. The zinc oxide coating provides moderate corrosion protection suitable for indoor, controlled-environment, or dry-storage use. At 0.05 lbs and compact dimensions (1.4 x 0.45 x 2.8 inches), this jam nut integrates seamlessly into space-constrained assemblies without adding significant weight. The 11/16-18 size makes it compatible with corresponding threaded studs and shafts in mechanical assemblies, firearms components, and industrial applications where dual-nut locking is employed.

This component is suited for gunsmiths, armorers, industrial technicians, and equipment maintainers who need reliable left-hand fastening solutions. Jam nut pairs are commonly used to lock adjustable components in place—such as barrel extensions, gas tube assemblies, or precision machinery shafts—where conventional single-nut installations cannot provide sufficient hold-fast security. The steel construction and zinc oxide finish balance durability with affordability, making it a practical choice for both original equipment and repair applications.