What Filler Metal Should be Used to Weld Carbon Steel to Stainless Steel

And can you use stainless wire to weld carbon steel to carbon steel

It is not uncommon to find fabricating shops that are welding a variety of metals including carbon steel, stainless steel, aluminum and nickel alloys.  In many cases some of these materials need to be welded to other types.  Once very common situation, especially in automotive applications is welding carbon steel to stainless. One of the […]

The Advantage of Using Undermatching Filler Metals on High Strength Steels

High strength steels are becoming more and more popular in steel construction.  Higher strength means we can reduce the thickness of the base material and thus reduce weight.  This is very important not just in vehicles but in static structures as well.   However, higher strength steels usually bring about a few issues that if not […]

Preheat and Interpass Temperature for Structural Steels

Preheating of structural steels is carried out primarily to slow the cooling rate after welding and prevent the formation of martensite.  Martensite makes the weld and the heat affected zone (HAZ) very hard and brittle.  This newly formed microstructure is susceptible to cracking.  By slowing the cooling rate we reduce or eliminate the formation of […]

The 9 Clauses of AWS D1.1 Structural Welding Code Explained

The most widely used welding code in North America, and perhaps the world, is AWS D1.1/D1.1M Structural Welding Code – Steel.  It is specified as the quality standard in hundreds of contract documents every year.   Yet, we find that less than half of the fabricators that need to use it have a sound understanding of […]

6 Mistakes That Can Lead to Cracked Welds

Cracks on welds are never good.  Welding codes always have allowances for porosity, undercut, weld sizes, and even weld profiles.  However, there is never an allowance for cracks.  Being a linear discontinuity, a crack will tend to propagate through the weld and into the base metal with relative ease, especially in cyclically loaded structures.  So […]

Which Welding Process Produces the Strongest Welds


This is a question that is often asked.   The short and quick answer is: they are all the same.  However, to understand why that is let’s take a quick look at the three elements that determine the strength of a weld: Weld length Weld size Weld (filler) metal strength Since we are trying to compare […]

Protecting Your Eyes from the Welding Arc: Welding Shade Numbers and Safety Glasses

Have you ever had your eyes burned by the welding arc rays? Was it because you didn’t wear safety glasses at work?  Or did you weld without a welding helmet?  Regardless of the reason, if you got an arc burn you better be ready for a very unpleasant night.  If you burn your eyes at […]

The Importance of the Heat Affected Zone (HAZ)

When we weld we generate enough heat in the welding arc to melt the filler metal and base material.  Or just the base material is we are welding autogenously (as in GTAW without filler).  The edges of the base material melt and combine with the filler metal to create what is called the composite zone.  […]

21 Changes to PQR Essential Variables that Require WPS Requalification

​Have you ever seen a welding procedure specification with established amperage ranging from 200 to 550 amps?Or voltage ranging from 21 to 29 volts?Or some other variable with a huge window?This is all too common, but extremely dangerous. Why? Because changes to essential variables beyond that which is reasonable will affect the physical and mechanical […]

The Reason Behind Minimum Fillet Weld Sizes

It's not what you think

Have you ever noticed that there are design rules that prohibit sizing a fillet weld below a certain size for a given thickness of material? If you look at AWS D1.1/D1.1M:2015 Structural Welding Code (Steel) you can find this on Table 5.7.   If you happen to own a copy of AISC 360-16 Specification for Structural […]