In terms of popularity, 304 grade is the reigning champion of austenitic stainless steels. But there’s a challenger called 304L with its own merits for commercial and industrial projects. So, who should you bet on in the matchup of 304 vs. 304L stainless steel?
(Need a full chart of stainless steel grades? Check this out.)
304 Vs. 304L Stainless Steel: Tale of the Tape
Besides the “L,” what’s the difference between these two stainless steel grades? Much like with 316 vs. 316L stainless steel, it’s the carbon content.
In this corner ...
- Grade 304, with a maximum carbon content of 0.08%.
And in this corner ...
- Grade 304L, with a maximum carbon content of 0.03%
The lower carbon content in 304L makes it even better for welding than standard 304. The low-carbon grade is usable "as welded" in severely corrosive environments and eliminates the need for annealing. — nice when your project needs a quick turnaround.
Type 304 has good welding properties too, but it’s more likely to sustain decay at the weld’s joints.
Some other attributes to take into consideration:
- Type 304 boasts strong corrosion resistance, tensile strength, and yield strength. It also has good drawability and formability -- your vendor can form it into a variety of shapes.
- Type 304L includes slightly lower mechanical properties than standard 304 -- tensile and yield strength are a bit lower. So anything you make out of 304L will be structurally weaker than something made with 304. Still, 304L is gaining popularity thanks to its versatility.
“But what about price?” you ask. There’s actually little to no difference between the prices of 304 and 304L (depending on market conditions).
304 Vs. 304L: Applications
Grade 304 stainless steel is popular in the food industry. It's great for beer and coffee brewing, milk processing, and wine-making because it’s resistant to the elements involved and it’s easy to clean.
Along those lines, industry folks use 304 in:
- Storage tanks
- Yeast pans
- Fermentation vats
Type 304 can withstand corrosion caused by chemicals inside fruit and meat. That’s why it’s also common in:
- Sinks and tabletops
- Kitchen appliances
- Cooking utensils
Outside, this grade sees frequent use in architecture.
Type 304L is also popular in beer brewing and wine making. Outdoors, companies often take advantage of 304L’s corrosion resistance for construction projects.
You’ll often find type 304 in mining and water filtration systems and in the dyeing industry. Other chemical-heavy places you’ll see 304 include:
- Heat exchangers
- Chemical containers
- Mining equipment
- Screws, nuts, and bolts in marine components
304L’s purposes are pretty much identical: chemical containers, mining tools, and the like. Engineers also use 304L in metal parts that will endure saltwater exposure. That said, if you want the most marine-ready stainless steel, you’re usually better off with 316.
And the Winner Is ...
In truth, both 304 and 304L can be used for many of the same applications.
Manufacturers often create commercial steel as “low-carbon” due to advances in modern steel making. Finished products often go on the market with branding that indicates they’re “dual certified” for 304 and 304L. This classification indicates you can use those products in fabrications specifying either grade.
That said, if your project requires lots of welding, 304L is your winning bet. If you want more structural strength, 304 prevails by unanimous decision.
Does your project require both welding AND forming fabrications? Ask your manufacturing vendor which metal you should choose.