The Fabricators Choice Since 1970

December 30, 2021

Weld nuts are one of the most underappreciated and underrecognized industrial fastener products. Both standard spot and projection weld nuts provide an effective way to permanently attach a fastener to a metal workpiece, allowing additional fasteners or parts to be added to the initial workpiece. Weld nuts are available in several sizes and styles for a broad range of applications.

Weld Nut Classifications & Material Options

Weld nuts are commonly manufactured from stainless steel (to enhance corrosion resistance) or low carbon steel materials. These materials allow the weld nut fastener to be protected from all types of environmental stresses, including highly corrosive salts and acidic materials with the use of 316 S.S.
  • Thickness
  • Shape
  • Size

Weld Nut Configurations & Classes

Whether your application requires a weld nut that can withstand light-, medium-, or heavy-duty loads, there is a configuration that provides the features that match your project specifications. The hex weld nut is suitable for a wide range of heavy-duty applications, while tab nuts are best for lighter applications.

Spot Weld Nuts

Tab weld nuts are specifically designed to be spot welded onto flat applications. These types of weld nuts are also manufactured with a locating boss around the base threads, which assists in locating the pilot hole. When space limitation is a primary concern, tab spot weld nuts provide an effective solution that will accommodate several electrode sizes for use in a standard production/fabrication environment. Spot weld nut options include:
  • Single tab
  • Double tab
  • Twin pilot
  • Single tab with target

Projection Weld Nuts

Tab projection weld nuts are ideal for heavier gauge materials and can be applied to flat or curved surfaces. Projection weld nuts feature a single projection that facilitates a strong and penetrating weld. Projection weld nuts are available with several projection configurations, some of which include:
  • Single projection
  • Dual rib projection
  • Four projection
  • Hex-3
  • Hex, six projection
  • Square projection

How are Weld Nuts Installed?

Weld nuts are most commonly installed using resistance welding techniques that utilize the right balance of pressure, current, and time. Using a regulator that modifies the primary and secondary voltage ratios for different current levels can assist in determining the proper heat level parameters.

Weld Nut Installation Parameters

Small low carbon steel weld nuts require a pressure range between 300 and 1,000 psi. The pressure can go up to 1,000 and 2,000 psi for the larger weld nuts. Meanwhile, more prominent ring projections require 4,000 psi pressure. The pressure for stainless steel weld nuts can vary between 1,500 and 5,000 psi.

Parameters for Weld Nut Resistance Installations

Resistance welding installs are quantified in cycle times. Each cycle is 1/60 of a second. The weld time may vary from 3 to 10 cycles for small fasteners. The weld time for larger fasteners may last between 10 and 20 cycles. A hold time of 20 to 30 cycles is required to ensure proper cooling of the welds.

Questions Regarding Weld Nuts?

For more information regarding weld nut fasteners or specific weld nut applications, contact Monroe-JHP Fasteners or check out our Fastener Installation Guide today. At Monroe-JHP Fasteners, we provide the weld nut solutions that meet or exceed your project needs.