Steel grades define the chemical composition and mechanical properties of the material. The grade determines what the steel can be used for, how it is priced, and how it should be handled. Every person at a steel service center, from the sales rep to the warehouse worker, should understand the grades they sell.
Carbon Steel Grades
ASTM A36. The most common structural steel grade. Minimum 36 ksi yield strength. Used in structural framing, base plates, gusset plates, and general fabrication. Weldable without preheat in most thicknesses. This is the bread and butter of most service centers. If you only stock one carbon plate grade, it is A36.
ASTM A572 Grade 50. Higher strength than A36 (50 ksi yield) with comparable weldability. Increasingly specified in structural applications where engineers want to reduce member sizes (thinner beams, lighter columns) without sacrificing strength. Many mills dual-certify material as both A36 and A572 Gr 50 if it meets both specifications.
ASTM A514. High-strength quenched and tempered plate. 100 ksi yield strength. Used in heavy equipment, crane booms, dump truck bodies, and applications where weight reduction matters. Requires preheat for welding and specialized welding procedures. More expensive and less commonly stocked than A36 or A572.
ASTM A1011/A1018. These specifications cover hot-rolled sheet and strip (A1011) and hot-rolled sheet, strip, and plate in coil form (A1018). They include multiple grades (SS Grade 36, SS Grade 50, HSLAS Grade 50, etc.) with varying strength levels. Most HRC that service centers sell falls under one of these specifications.
ASTM A1008. Cold-rolled carbon steel sheet. Grades include CS (Commercial Steel), DS (Drawing Steel), DDS (Deep Drawing Steel), and EDDS (Extra Deep Drawing Steel). The grade designates formability, with EDDS being the most formable. Important for customers who stamp, draw, or bend the material into complex shapes.
Stainless Steel Grades
304 (UNS S30400). The most common stainless grade, accounting for roughly 50% of all stainless production. Austenitic (non-magnetic in annealed condition). 18% chromium, 8% nickel. Good corrosion resistance in most environments. Used in food equipment, architectural trim, chemical processing, and general corrosion-resistant applications.
304L (UNS S30403). Low-carbon version of 304 (0.03% max carbon vs. 0.08% for 304). The lower carbon prevents carbide precipitation during welding, which can cause intergranular corrosion. Specified for welded fabrications in corrosive environments. Slightly lower strength than 304.
316 (UNS S31600). Contains 2% to 3% molybdenum in addition to the chromium and nickel in 304. The molybdenum provides superior corrosion resistance, particularly against chlorides (salt water, de-icing chemicals). Used in marine environments, pharmaceutical equipment, and chemical processing. More expensive than 304 due to the molybdenum content.
316L (UNS S31603). Low-carbon version of 316, with the same welding advantages as 304L. The most commonly specified stainless grade for welded fabrications in demanding corrosion environments.
410 (UNS S41000). Martensitic stainless (magnetic, heat treatable). 12% chromium, no nickel. Lower corrosion resistance than 304 but significantly harder. Used in cutlery, fasteners, valve components, and applications where hardness matters more than corrosion resistance.
What Sales Reps Need to Know
You do not need to memorize the chemical composition of every grade. You need to know three things about each grade you sell: what it is used for (so you can match the grade to the customer's application), how it compares to alternatives (so you can suggest options when the preferred grade is not available), and whether it has special handling or fabrication requirements (so you can communicate lead time and processing constraints accurately).
When a customer asks for a grade you are not familiar with, ask them about their application. The application usually narrows the grade options to two or three possibilities. Then verify the specific grade with your purchasing team or quality department before quoting.
Knowing your grades builds credibility. The sales rep who can discuss the difference between A572 Grade 50 and A588 weathering steel demonstrates expertise that differentiates them from the rep who just takes orders and looks up prices. Expertise builds trust. Trust builds loyalty. Loyalty drives revenue.