Different metal welds involving stainless steel can be done using most full fusion weld methods, including TIG (Tungsten Inert Gas) and MIG (Metal Inert Gas). Wondering whether a stainless steel nut could be welded to a carbon steel wire form.

Yes, stainless steel nut can be welded to a carbon steel wire, but you probably shouldn’t. If you need a corrosion-resistant wire form, it’s best to choose stainless steel wire instead of combining two or more metals.

How You Can Weld Different Metals

Different metal welds involving stainless steel can be done using most full fusion weld methods, including TIG and MIG). In many cases, when welding different metals such as stainless and plain carbon steel, weld processes such as MIG welding that use filler material are preferred.

As there are variations in electrical conductivity between stainless steel and carbon steel resistance welding of the two isn’t generally done, because it is very tough to make them reach the proper welding temperature. When resistance welding is employed, typically carbon steel is preheated since it’s more electrically conductive and doesn’t heat up as quickly as stainless steel.

Reasons You Shouldn’t Weld Plain Carbon and Stainless Steel Wire

Difficulty- Welding different metals together add extra challenges to the process. This translates into increased labor, rejection/error rates, and costs.

Hot Cracking of the Stainless Steel- SS is more electrically-resistant than carbon steel, stainless heat up much quicker in electrical resistance welds than carbon steel. The stainless steel will overheat and become riddled with hot cracks while looking ahead to carbon steel to achieve weld temperature. Using filler-based welding or preheating the plain steel will improve the condition this, however, these methods aren’t ideal.

Thermal Expansion in High-Temperature Service Conditions- Another drawback of using different metals in a welded wire form is that thermal expansion from heat can have an effect on each metal differently. This distinction in expansion rates between the two metals can cause further fatigue to the welded joint—reducing the wire form’s structural integrity and helpful life.

Increased Bimetallic Corrosion- the main reason you want to use stainless steel is because of its strong resistance to corrosion. An uncovered weld of plain and stainless steel that is exposed to extremely corrosive conditions, such as immersion in saltwater, could cause corrosion. This is due to the mix together of plain steel particles with the stainless alloy compromises the protective oxide layer of the stainless, allowing rust to form.

Reduced Weld Strength- Even with filler-based welding methods the problem with joining different metals is that it can lead to weaker welds. The differences in weld temperatures and operational tolerances alone can easily compromise the strength of the welded joint.

To boil it down, welding different metals together is difficult to do, and often produces inferior results to using metal alloys that are similar or the same.

By taking into account the long-term effects of using different metal alloys in a custom wire form, you can make sure that you get the right method for the job.