Hot Formed Steel vs. Cold Formed Steel

There are more than 3,500 different grades of steel each having their own unique properties.  With all the different types it allows for wide diverse use in infrastructure, appliances, vehicles, even wind turbines.  Optimizing steel properties goes well beyond changing the chemical composition.  However, the manufacturing process plays a role in steel products even if the grades of the steel are the same.  

What is the difference between hot rolled steel and cold rolled steel?

The difference to note between both rolling methods is the process in which they are done.  Hot rolled steel takes place when heat is applied.  For cold rolling it is the opposite of hot rolled steel it happens at or near room temperature.  Both of these techniques play a role in overall performance and application.  Steels of all types of grades and specifications can be rolled both hot or cold.  That includes basic carbon steel and other alloy steels.  

Hot Rolled Steel

Hot-rolled steel is steel that has been heated up to extreme temperatures (over 1,700 degrees) which is well over the recrystallization temperature for the majority of steels.  This allows the steel to be able to be bent and shaped easier.  How is works is that manufactures start with a large piece of metal called a billet.  They begin by heating the billet before it is sent for pre-processing where it gets flattened into a large roll.  From there it is run through a series of rollers while being kept at a high temperature till it takes its final dimensions.  Sheet metal is a bit different of a process.  The rolled steel is spun into coils and left to cool.  Where they are made into bars, or plates.  

Benefits of Hot Rolled Steel

When it comes down to rolling steel there are two options to either hot roll it or cold rolling.  Hot rolling steel requires much less processing which is more cost effective. Hot rolling steel is the better option when dimension tolerance are not as important as overall material strength. 

Cold Rolled Steel

The process for cold rolling steel takes a bit longer as it involves just a few more steps compared to hot rolled steel.  Each product of cold rolled steel or sheets are pulled like bars and tubes.  Other cold finishing processes include turning, grinding, and polishing, each of which are used to modify the existing hot rolled steel into a more refined product.  

Benefits of Cold Rolled Steel

The first aspect that is noticeable between cold rolled steel and hot rolled is the surface characteristics.  So, when the job calls for more precise applications cold rolled steel will provide a more aesthetic feel.  The baring part of using cold rolled steel is the price tag that comes along with it.  Due to it having more steps and applications to get to the finished product.  Another winning aspect cold rolling brings to the table is the strength and resistance to tension.  

Contact Markham Metals Today!

If you are looking for an expert team to help with your next project do not overlook Markham Metals.  Our professionals have years of experience with cold and hot rolling metals. For more information on cold and hot rolling metals read more here.  To get in contact with us at 978-658-1121 or by filling out an online contact form.  

Metal cutting breaks down into two categories there is mechanical cutting and then thermal cutting.  Plasma cutting falls underneath the thermal cutting method that relies on ionized gas to cut through metals.  Plasma cutting is one of the most widely used techniques to cut thick metal plates and sheet metal.  Below we weigh the benefits and disadvantages of plasma cutting.  

What is Plasma?

It is possible to find plasma in nature but mainly in the upper parts of Earth’s atmosphere.  The beautiful polar lights that everyone has heard of are actually made up of solar winds made of plasma.  There is plasma found in other areas too such as our bodies, and even lightning.  Plasma is all around us in the universe everywhere we look.   

Plasma is an electronic conductive ionized gas-like substance.  Gas can be transformed into plasma if it is introduced to intense heat.  Similar to gasses, plasma atoms are not in constant contact with each other.  At the same time it holds similar qualities of behavior as liquid with the ability to flow when subjected to an electrical and magnetic field.  

How Does Plasma Cutting Work?

Plasma cutters use compressed air and gasses like nitrogen.  Once the gas ionizes they become plasma.  With the mixture of plasma making contact with electrodes it creates pressure.  Then, a build up of pressure begins to push the plasma towards the cutting head.  The cutting force is then directed towards the workpiece.  While the plasma is contacting the metal the high temperature begins to melt it.  Lastly, the gasses traveling at a high speed blow away the molten metals.  

The Cutting Process

Now, even though not all cutting processes are the same there are different variations of plasma cutting.  Ones that are a lot less costly.  Like, the high frequency method, the pilot arc, or even the spring loaded plasma torch head.  There are pros and cons for each method and a time to choose which one is best for your project.  

Advantages vs. Disadvantages

Advantages 

• Able to cut all conductive materials
• Great quality for thickness up to 50 mm
• Maximum thickness up to 150 mm 
• Comparative cheap for thick metal cutting
• Best way to cut medium thickness stainless steel and aluminum
• Can cut in water 
• Smaller cutting kerf compared to flame cutting 
• Quick cutting speed

Disadvantages

• Larger Haz compared to laser cutting 
• Quality with thinner sheets and plates is not as good as laser cutters.  
• Tolerance is not as precise 
• Does not reach thickness like flame cutting or waterjet cutting 
• Wide kerf

Choosing a Cutting Method

The recommended cutting thickness for plasma cutting is between 15 and 50 mm.  The recommended upper limit of material thickness for a plasma cutting service is around 50 mm for both carbon and stainless steel.  Aluminum should never go beyond 40 mm.  Everything that exceeds these limits should be done with either flame cutting or waterjet cutting.  When it comes to thinner metals like sheet metals laser cutting is the ideal choice.  

Contact Markham Metals Today:

For more information on plasma cutting contact our team of professionals at Markham Metals.  Our team is more than happy to help with both small and big projects.  To get in touch with us call us at 978-658-1121 or by filling out an online contact form directly on our website.  We look forward to speaking with you.