Is There a Difference Between 303 Stainless Steel and 304?

Stainless steel provides an array of benefits, from corrosion resistance to stain and rust durability.  However, when comparing 303 to 304 stainless steel, you’ll notice a similar makeup with a very dissimilar property balance. As experts in the metal industry, Alliant Metals is here to set the record straight.

This article provides a brief overview of the two kinds of steel and how to determine which one is right for your application.



304 Stainless Steel


Among the most popular stainless steel alloys, 304 stainless steel is a prized steel in several industries. Suitable for most welding jobs with low carbon content, cost-effective for industrial kitchen solutions, and hosting superior rust and corrosion-resistance for architectural and automotive components, one can quickly see the multitude of benefits.

Unlike other forms of stainless steel, 304 is not conductive. This means that 304 does not transfer electricity or heat well. While this feature is undesirable in some applications, it is another highly desirable property for specific industries like those mentioned above.


304 stainless steel



303 Stainless Steel


A free-machining grade of 304, 303 stainless incorporates the addition of sulfur to increase its machinability.  Particularly desirable for automatic operations, 303 also maintains the mechanical and corrosion resistance properties common to stainless steel.  More accessible to machine than 304, 303  has controlled amounts of manganese sulfides. This addition causes the machining chips to break easily.

Another vital factor about the two is 303 is not easily welded due to the higher sulfur content, whereas 304 can be. For the same reason, 303 is not manufactured as sheet metal, tube, or angle due.



Choosing between 304 stainless steel and 303 comes down to the intended use and if machining is a prominent part of the job.  Where 303 is specifically designed to handle machining applications, 304 is the better option for welding.

No matter what the application requires, Alliant Metals can supply you with the solution your job needs.  For more information, please contact our team today by calling (800) 543-1453.

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