The Most Common Welding Metals and When to Use Them.
Do you have a welding project in mind, but you aren’t sure what material to buy? Fortunately for you, we are here to explain the most common metals and when you should use each one. There are 3 main metals used in most welding projects. They are as follows:
1) Carbon Steel
2) Stainless Steel
So how do we choose which one to use? Well first we need to understand the important properties of each.
Understanding The Properties
There are 5 main traits we will focus on for these metals. They are defined below for you
Ductility – How much you can shape or bend the metal before it breaks
Strength – How much pressure or force can be exerted onto the metal
Melting Point – How much heat needs to be applied before it can be liquified
Weight – How heavy the metal is
Corrosion – How prone the metals are to rusting
These traits vary with each metal and should be determining factors when you are deciding between each metal. Now lets take a look at the metals!
Carbon Steel is a metal alloy composed primarily of iron, and up to 2% of carbon. Due to the variations of how much carbon is added, steel can have a wide range of ductility as well as strength. In short, the higher the strength of the steel, the lower the ductility, and vice versa. This is usually determined by how much carbon is used in the alloy.
High carbon steel is very strong, and great for structural applications, but is not very flexible. Low carbon steel on the hand, is much more flexible, and is more commonly used in automobile bodies, but lacks some of the strength of the higher carbon steel. Medium carbon steel lands right in between the two in terms of strength and ductility. Steel is rated as high carbon if it has between .55% all the way up to 2% carbon in its composition. Medium carbon is .25% to .55%, and low carbon steel is .25% carbon and under.
Carbon steel is a very heavy metal, and weighs roughly 489 lbs. per cubic foot. This heavy weight is important to account for when using steel. One of the downsides to using Carbon steel, is that it is susceptible to corrosion. While it boasts higher tensile strength than its counterpart in stainless steel, carbon steel can quickly rust when exposed to too much moisture. In fact just the moisture in the air can be enough to lead to rust forming.
Carbon steel has a melting point between 2600-2800 F. This number varies based on how much carbon is in the steel, with higher levels of carbon leading to lower melting points. While this number may seem large, a temperature of over 2800F is easily achieved by any of the 4 most common welding styles. For more information about the 4 most common types of welding, check out our other blog post about the welding styles!
Stainless steel starts off with iron, the same way that carbon steel does, however it adds between 10-30% chromium. This chromium is important because unlike iron, chromium is resistant to oxidization. This oxidization is what leads to steel rusting and turning that brownish red color. Stainless steel lives up to its namesake because it simply does not rust the same way that normal steel does.
Stainless steel can be a very ductile metal, when compared to high carbon steel. It does however lack the same tensile strength that high carbon steel can have. Stainless steel is more commonly used in the restaurant and medical industries, as it is very easy to sanitize and clean. It does however weigh just about as much as carbon steel, coming in at 490 lbs. per cubic foot.
Stainless steel has a melting point similar to carbon steel, melting at 2750F. This means that also like carbon steel, stainless steel can be used with any of the 4 most common types of welding. The biggest downside to using stainless steel, is its cost. Stainless steel is incredibly expensive when compared to regular steel, often costing as much as 5 times the price.
The final commonly used metal, is Aluminum. Aluminum has similar corrosion resistance to stainless steel. It is incredibly ductile, making it very versatile to use in product creation. The downside to aluminum, is its lack of tensile strength when compared the previous two metals. It is also incredibly lightweight when compared to the previous two metals, coming at almost one third the weight of them. Aluminum weighs roughly 168 lbs. per cubic foot.
The main advantages to aluminum are the low corrosion, combined with the lightweight properties, as well as the high levels of conductivity. This makes it an ideal metal to weld for electrical applications and machinery. The lightweight nature makes it highly portable and easy for mobile welding applications.
Pure aluminum has a melting point of roughly 1220F, however aluminum alloys can melt at temperatures as low as 900F. This low temperature means it can be welded using any of the 4 popular techniques, as well as allows it to be used well as a filler metal. In terms of price point, aluminum is typically cheaper than stainless steel, but still more expensive than carbon steel.
So Which Should You Use?
Well now you know the differences between them, and the recomended applications for each metal. Of course, there are other metals you can use, and depending on the application, we may even recommend a specific one. Lucky for you, we are here to help you decide which metal to use and when. We offer welding consultations and mobile welding services throughout all of Southern California. Feel free to fill out the consulation form below to schedule your consulation!