In This Article
Order the wrong steel grade and you're either overpaying for strength you don't need — or underspeccing a member that has to carry real load. Here's everything you need to know to get it right.
Most contractors know the names — A36, A572, A992 — but fewer know exactly what the differences mean on the job. This guide breaks down every major structural steel grade in plain language so you can spec confidently, order correctly, and never have to call your engineer for a basic material question again.
⚠ Why Steel Grade Matters More Than You Think
Steel grade isn't just a spec on a drawing — it directly affects your project's safety, cost, and schedule. Getting it wrong can mean:
Over-ordering strength you don't need — A572 costs 2.5–5% more than A36. On large orders that adds up fast, especially when A36 would have been more than adequate.
Failing inspection — Commercial and municipal projects require specific ASTM grades. Substituting without engineer approval can fail inspection and require costly rework.
Welding problems — Different grades require different preheat temperatures and filler metals. Using the wrong procedure on the wrong grade leads to weak welds and potential failures.
Reorders and delays — Ordering the wrong grade means waiting on a second shipment, which can blow your project schedule entirely.
▶ A36 — The Workhorse Grade
ASTM A36 is the most widely used structural steel grade in the United States. It's a mild, low-carbon steel that offers an excellent balance of strength, weldability, and cost. If your drawings don't specify a grade, A36 is almost certainly what's expected.
Best for: General construction, building frames, base plates, gusset plates, brackets, angle iron connections, beams in light-to-moderate load applications, and any project where ease of fabrication and budget matter most.
▶ A572 Grade 50 — The High-Strength Upgrade
A572 Grade 50 is 39% stronger than A36 — meaning you can use lighter, thinner sections to carry the same load. On large-scale projects this weight savings can reduce material costs enough to offset the slightly higher price per pound.
Best for: Heavy structural applications, bridges, high-rise frames, crane booms, transmission towers, heavy equipment bases, and any project where weight savings and higher load capacity matter.
▶ A992 — Built for Beams and Columns
A992 is specifically engineered for wide-flange (W-shape) beams and columns in structural building frames. It offers the same yield strength as A572 Grade 50 but with tighter chemistry controls and a capped yield-to-tensile ratio — making it safer and more predictable in seismic and high-stress applications.
Best for: Wide-flange beams and columns in commercial buildings, high-rise structures, seismic zones, and any application where AISC 360 compliance is required. If your drawings specify W-shapes, A992 is almost certainly the required grade.
▶ A500 — For HSS Tubing and Hollow Sections
ASTM A500 Grade B is the standard for cold-formed hollow structural sections (HSS) — the square, rectangular, and round tubing you see in columns, trusses, railings, and architectural framing. It's stronger than A36 and is the default grade when your drawings spec HSS members.
Best for: Square and rectangular HSS columns, trusses, space frames, canopy structures, handrails, and any application where a clean, consistent tube profile is needed.
📋 Grade Comparison at a Glance
Use this table to quickly compare the four grades side by side before you spec your order.
✅ How to Pick the Right Grade for Your Project
Answer these four questions and you'll land on the right grade every time:
❓ Frequently Asked Questions
Know Your Grade. Get Your Quote.
We stock A36, A572, A992, and A500 — all grades, all shapes, cut to your spec.
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A36 Steel A572 Grade 50 A992 Wide Flange A500 HSS Tubing Angle Iron Steel Plate Flat Bar Aluminum