- Round base nuts
These nuts have a long threaded cylinder with a large circular base to make welding easy. They also sometimes have projections (known as weld nibs or bosses) to keep the nut from warping while welding with a high current.
- Slab base nuts
- Tab base nuts
- Hex & square nuts
These nuts are very similar to standard square or hex nuts, but have a locating boss and welding projections. The bosses also keep weld spatter out of the threads.
- Retainer weld nuts
Retainer weld nuts, also known as bridge weld nuts, have a floating nut retained inside a retainer to compensate for inconsistencies. The retainer is welded to the workpiece while the nut is allowed to float.
- Tube end nuts
Tube end nuts are sized to fit into the end of standard sized tubing, thus creating a threaded tube from standard stock.
- Twin Piloted Nuts
Dual hole or twin piloted nuts are designed for use where there is a need for tapped holes close together.
The vast majority of weld nuts are manufactured in low carbon steel or stainless steel. This is due to the methods currently available to spot weld or projection weld the hardware to joining material. Aftermarket products such as zinc plating are sometimes used to coat low carbon weld nuts giving it the rust resistant properties of stainless steel at a substantial cost saving.
- McMaster-Carr catalog (114th ed.), McMaster-Carr.
- Buckeye Fasteners catalog (2018 ed.), Buckeye Fasteners Company.