Choosing the right steel grade can make or break a project. Use the wrong one and you’re looking at cracked welds, premature rust, or way more money spent than necessary. Use the right one and your finished product performs exactly as designed — for years.
At Ram Steelco, we stock the most common structural and mechanical steel grades and can help you figure out which one fits your job. Here’s a plain-language breakdown of the grades you’ll run into most often — what they are, what they’re best for, and where to find them in our online catalog.
A36 — The Workhorse of Structural Steel
ASTM A36 is the most widely used structural steel grade in the United States. It’s a low-carbon steel with a minimum yield strength of 36,000 psi, which makes it strong enough for the vast majority of construction and fabrication work without being difficult to weld or machine.
Key properties:
- Carbon content: 0.25–0.29%
- Yield strength: 36,000 psi (minimum)
- Tensile strength: 58,000–80,000 psi
- Excellent weldability — no preheat needed in most cases
- Easy to drill, saw, punch, and shear
Common uses: building frames, bridges, equipment bases, trailer frames, brackets, gusset plates, and general structural fabrication.
You’ll find A36 across most of our hot rolled products: plate, sheet, flat bar, angle, channel, I-beam, wide flange, and round bar.
Browse all A36 hot rolled steel →
A572 Grade 50 — When You Need More Strength
ASTM A572 Grade 50 is a high-strength, low-alloy (HSLA) structural steel. With a minimum yield strength of 50,000 psi — about 39% stronger than A36 — it lets you use lighter sections to carry the same load. That means less material, lower weight, and often lower cost on larger projects.
Key properties:
- Carbon content: 0.23% max
- Yield strength: 50,000 psi (minimum)
- Tensile strength: 65,000 psi (minimum)
- Good weldability (comparable to A36)
- Often dual-certified with A36 on plates and shapes
Common uses: heavy structural applications, bridges, high-rise building frames, crane booms, heavy equipment, transmission towers, and any project where weight savings matter.
A572 Grade 50 is commonly available in our plate, I-beam, wide flange, channel, and angle inventory.
1018 — The Go-To for Cold Drawn Bar Stock
AISI/SAE 1018 is a low-carbon steel commonly used for parts and components that need to be machined, welded, or case-hardened. It’s the most popular grade in cold drawn bar stock because it combines easy machinability with a smooth, consistent finish.
Key properties:
- Carbon content: 0.15–0.20%
- Yield strength: ~54,000 psi (cold drawn)
- Tensile strength: ~64,000 psi (cold drawn)
- Excellent machinability and weldability
- Can be case-hardened for a tough exterior with a ductile core
Common uses: shafts, pins, studs, spacers, bushings, fixtures, machine components, and general-purpose parts.
We stock 1018 in cold drawn round bar, cold drawn flat bar, cold drawn square bar, and cold rolled hex bar.
4140 — High-Strength Alloy for Demanding Applications
AISI/SAE 4140 is a chromium-molybdenum alloy steel that offers significantly higher strength and hardness than 1018. It’s often used where parts will see high stress, impact, or wear. It can be heat-treated to reach very high hardness levels while maintaining good toughness.
Key properties:
- Carbon content: 0.38–0.43%
- Yield strength: ~60,000 psi (annealed); much higher when heat-treated
- Tensile strength: ~95,000 psi (annealed); 150,000+ psi heat-treated
- Good fatigue resistance and impact strength
- Weldable with preheat and proper procedures
Common uses: axles, shafts, gears, bolts, collets, hydraulic cylinders, tooling, die holders, and high-stress structural components.
4140 is typically available as round bar. Request a quote for specific sizes and lengths.
Quick Comparison: A36 vs A572 vs 1018 vs 4140
| Property | A36 | A572 Gr 50 | 1018 (CD) | 4140 (Ann.) |
|---|---|---|---|---|
| Yield strength | 36 ksi | 50 ksi | 54 ksi | 60 ksi |
| Tensile strength | 58–80 ksi | 65 ksi min | 64 ksi | 95 ksi |
| Carbon content | 0.25–0.29% | 0.23% max | 0.15–0.20% | 0.38–0.43% |
| Weldability | Excellent | Good | Excellent | Fair (preheat) |
| Machinability | Good | Good | Excellent | Good |
| Heat treatable | No | No | Case harden only | Yes — full |
| Best for | Structural, general fab | Heavy structural | Machined parts | High-stress parts |
How to Pick the Right Grade
Choosing a steel grade comes down to three questions:
- What loads will it carry? — If you need basic structural strength, A36 handles most jobs. For heavier loads or weight-sensitive designs, step up to A572 Grade 50.
- Will it be machined? — If you’re turning, milling, or drilling the part, 1018 cold drawn is your best bet for clean results. For high-performance parts under heavy stress, go with 4140.
- How will it be joined? — A36 and 1018 weld easily with standard procedures. A572 is nearly as simple. 4140 requires preheat and post-weld heat treatment — plan accordingly.
Still not sure? Our sales team deals with grade selection questions every day. Give us a call or submit a quick quote with your project details and we’ll point you in the right direction.
Need It Cut to Size?
We don’t just sell metal — we process it. Every grade we stock can be cut, formed, or shaped to your specs in-house:
- Laser cutting — precision parts from plate and sheet
- Hy-Def plasma cutting — fast cuts on thicker plate
- Shearing — straight cuts on sheet and plate
- Forming — bends and angles on a CNC press brake
- Saw cutting — bar, tube, and structural shapes cut to length
Read our full breakdown: Your Complete Guide to Metal Processing Services at Ram Steelco →
Ready to Order?
Whether you need a single bar or a full truck of plate, here’s how to get started:
- Shop online — Browse our full catalog, select your grade and size, and add to cart.
- Request a quote — Need custom processing or large quantities? Use our Quick Quote form.
- Call us — Talk to our team at 503.588.1311 for help with grade selection, availability, or delivery.
We offer local delivery throughout Oregon and ship nationwide. Get your quote today →
