As a nationwide supplier of prime, excess, and secondary flat rolled steel products, the Mainline Metals team works closely with purchasing managers, shop foremen, and operations teams to provide the steel materials they need, on time and on spec. 

This guide outlines the types of flat rolled steel products we offer, including hot rolled, cold rolled, galvanized, and coated materials, as well as sheet, plate, and structural steel formats.

What Is Flat Rolled Steel?

Flat rolled steel is a type of processed metal that has been passed through a series of rollers to achieve a flat, uniform thickness. It is typically produced in two main forms: sheet (cut to specific dimensions) and coil (wound into large rolls for easy handling and transport). This rolling process can be performed at high temperatures (hot rolled) or at ambient temperature (cold rolled), depending on the desired material properties and end use.

Flat rolled steel serves as the backbone of a wide range of industries. It’s used in everything from structural steel components in buildings and bridges to automotive body panels, household appliances, and industrial machinery. Its widespread use is largely due to its versatility, formability, and cost-efficiency.

In addition to its physical flexibility, flat rolled steel can be coated or treated to improve performance. Common coatings include zinc (galvanized), aluminum-zinc (Galvalume), and zinc-iron (galvanneal), each offering varying levels of corrosion resistance, paintability, and durability in different environments.

Overall, flat rolled steel is a critical material for both heavy industry and consumer products. With the right processing and finish, it can be tailored to fit nearly any application.

Types of Flat Rolled Steel Products We Offer

At Mainline Metals, we supply a wide range of flat rolled steel products to meet the diverse needs of our customers. Whether you’re sourcing material for construction, fabrication, or manufacturing, we offer multiple grades, finishes, and coatings to fit your application. 

Below is a breakdown of some of the variety of flat rolled steel products we carry and what they’re commonly used for.

Hot Rolled (HRC) Steel

Hot rolled steel is the most widely used and fundamental type of flat rolled steel. Produced by rolling steel slabs at temperatures above 1,700°F, hot rolled steel is easier to form and shape at these elevated temperatures, making it ideal for applications where precise dimensions and surface appearance are not critical.

As the steel cools after rolling, it shrinks slightly, which can result in minor variations in size and finish. However, this doesn’t affect its overall performance in structural or industrial settings. Because of its cost-efficiency and strength, hot rolled steel is frequently used in projects that require durability and load-bearing capacity without a polished appearance.

Common Applications:

• Construction beams and columns
• Agricultural and farming equipment
• Heavy machinery frames and supports
• Truck frames and rail components
• General fabrication work

Key Benefits:

• Lower production costs make it an economical choice for large-scale projects.
• Maintains excellent mechanical properties, making it suitable for heavy-duty applications.
• Its ductility allows for easy bending, cutting, and welding during fabrication.

Hot rolled steel is a workhorse in the industry—perfect when strength and function matter more than surface finish.

Hot Rolled, Pickled & Oiled (HRPO) Steel

Hot rolled, pickled, and oiled (HRPO) steel is a cleaned-up version of traditional hot rolled steel. After the steel is hot rolled, it goes through a pickling process that removes the scale—a layer of oxidized iron that forms during high-temperature rolling. Then, it’s coated with a light layer of oil to prevent rust and oxidation during storage and transport.

The result is a product that offers the strength and workability of hot rolled steel but with a smoother surface finish, making it easier to coat, form, and weld in downstream processes.

Common Applications:

• Automotive parts such as brackets and structural components.
• Tubing and pipe manufacturing.
• Industrial storage tanks.
• Racks, shelving, and warehouse systems.
• Fabricated metal parts requiring painting or coating.

Key Benefits:

• Cleaner surface finish than traditional hot rolled.
• Reduced risk of rust during transit and storage.
• Excellent for welding, painting, and forming.
• Maintains structural integrity of hot rolled steel.

Cold Rolled (CR) Steel

Cold rolled steel is made by rolling hot rolled steel at room temperature. This secondary rolling process improves dimensional accuracy, tightens tolerances, and results in a smoother, more refined surface. It also increases the steel’s strength due to strain hardening.

Cold rolled steel is perfect for applications where aesthetics and precision matter. It’s often used in consumer-facing products and precision-engineered components.

Common Applications:

• Home appliances like washers, dryers, and refrigerators.
• Metal office furniture and cabinets.
• Precision parts for mechanical systems.
• Shelving, lighting fixtures, and electrical enclosures.
• Automotive panels and components.

Key Benefits:

• High strength and stability due to strain hardening.
• Superior surface finish suitable for painting or coating.
• Excellent dimensional accuracy.
• Ideal for tight-tolerance applications.

Cold Rolled Full Hard Steel

Cold rolled full hard steel is produced through the cold rolling process but does not undergo annealing, which means it retains its maximum hardness and strength. However, this makes it less ductile and more brittle, so it’s typically not used in applications that require bending or shaping unless further processing (like annealing or coating) is planned.

This type of steel is commonly used upstream in manufacturing as an input for galvanized or coated products.

Common Applications:

• Automotive parts where additional processing will follow.
• Tube making and roll forming.
• Pre-painted steel products.
• Structural parts that will be annealed or galvanized.

Key Benefits:

• Maximum strength and hardness.
• Cost-effective base material for coated or annealed products.
• Suitable for long production runs in coil form.
• Ideal for structural stability when post-processing is planned.

Galvanized Steel – Sheet

Galvanized sheet metal is steel that has been coated with a layer of zinc via a hot-dip process, forming a barrier that protects the underlying steel from rust and corrosion. This makes it ideal for outdoor or high-moisture environments.

It’s a go-to material for both structural and functional uses where long-term durability is important.

Common Applications:

• Roofing and siding in residential and commercial buildings.
• HVAC ductwork and components.
• Fences, gates, and guardrails.
• Outdoor signage and enclosures.
• Agricultural equipment.

Key Benefits:

• Exceptional corrosion resistance.
• Long-lasting protection in outdoor environments.
• Easy to fabricate, weld, and paint.
• Affordable and typically widely available.

Galvanized (HDG) Steel – Coil

Hot-dip galvanized (HDG) coil is the coil form of galvanized sheet metal. It provides the same corrosion-resistant benefits, but in a more flexible, efficient format for large-scale fabrication, stamping, or roll-forming operations.

This format is ideal for manufacturers who require custom lengths or automated processing capabilities.

Common Applications:

• Metal framing systems.
• Garage doors and access panels.
• Formed components for HVAC and construction.
• Automotive underbody parts.
• Storage units and lockers.

Key Benefits:

• High processing efficiency.
• Versatile use across industries.
• Available in various widths, gauges, and zinc coating weights.
• Consistent surface and protective performance.

Galvalume Steel

Galvalume is steel coated with a zinc-aluminum-silicon alloy that offers superior corrosion resistance especially in harsh or coastal environments. It combines the sacrificial protection of zinc with the barrier protection of aluminum, giving it longer service life than traditional galvanized steel in certain applications.

Common Applications:

• Metal roofing and wall systems.
• Pre-engineered metal buildings.
• Architectural panels and trim.
• Soffits, gutters, and flashing.

Key Benefits:

• Excellent corrosion resistance (especially in marine climates).
• Longer lifespan than traditional galvanized steel.
• Attractive spangled finish.
• Great for painted or unpainted applications.

Galvanneal Steel

Galvanneal steel is hot-dip galvanized and then annealed, creating a zinc-iron alloy coating that is tough, weldable, and easy to paint. This unique combination makes it ideal for applications requiring a strong surface bond with paint or primer.

It’s widely used in the automotive and appliance industries, as well as in construction.

Common Applications:

• Auto body panels.
• Electrical cabinets and panels.
• Door frames and casings.
• Appliance housings.
• General fabrication requiring painted finishes.

Key Benefits:

• Superior paint adhesion.
• Weldable and formable.
• Good surface hardness and scratch resistance.
• No flaking during forming or bending.

Painted Steel

Our pre-painted steel products are available in a variety of colors, textures, and finishes, eliminating the need for post-fabrication painting. These products are ready to use, saving time and cost while also delivering a polished, professional appearance right off the coil or sheet.

Painted steel is often used in applications where both appearance and corrosion protection are important.

Common Applications:

• Architectural panels and trim.
• Garage and entry doors.
• Metal buildings and carports.
• Appliance panels.
• Retail fixtures and displays.

Key Benefits:

• Factory-applied coatings ensure consistency and durability.
• Wide selection of colors and finishes.
• Saves time and labor on painting.
• Excellent weather and UV resistance.

Other Flat Rolled Steel Formats and Forms

While coils and sheet products are essential to many operations, flat rolled steel can also be formed into a variety of structural and fabricated shapes that serve specific functions in construction, manufacturing, and industrial applications. 

At Mainline Metals, we supply an extensive range of finished steel forms designed for load-bearing strength, ease of fabrication, and long-term durability.

Steel Sheet

Steel sheet is a flat rolled product available in a wide variety of thicknesses (gauges), widths, and surface finishes, making it one of the most versatile steel materials on the market. It’s thinner than plate and ideal for applications that require cutting, stamping, forming, or welding.

Steel sheets can be supplied as hot rolled, cold rolled, galvanized, or painted, depending on your performance and aesthetic requirements.’

Common Applications:

• Enclosures and metal casings.
• Roofing and siding panels.
• Ductwork and HVAC systems.
• Metal shelving and furniture.
• Automotive and appliance parts.

Key Benefits:

• Highly versatile and formable.
• Easy to fabricate and transport.
• Available in various coatings and finishes.
• Suitable for both indoor and outdoor use.

Steel Plate

Steel plate is the thicker cousin of steel sheet and is known for its strength and durability. Typically ranging from 3/16 inch thick and up, steel plate is used in applications that demand load-bearing performance and structural integrity.

It can be processed through flame cutting, welding, machining, and other fabrication methods, making it ideal for industrial and heavy-duty settings.

Common Applications:

• Construction equipment and machinery bases.
• Bridge decking and support structures.
• Shipbuilding and marine applications.
• Heavy transport vehicles.
• Structural foundations and platforms.

Key Benefits:

• Exceptional strength and impact resistance.
• Ideal for heavy-duty and structural applications.
• Can be custom cut or machined to spec.
• Available in a range of grades and sizes.

Steel Channel

Steel channel, also known as C-channel, features a U-shaped cross-section with two flanges on one side of a web. It’s widely used for framing, bracing, and support, particularly in structural applications where a lightweight yet strong component is required.

Available in multiple sizes and thicknesses, steel channels offer excellent torsional resistance and ease of connection with other materials.

Common Applications:

• Building frames and trusses.
• Stair stringers and guardrails.
• Racking systems and warehouse infrastructure.
• Machinery support frames.
• Vehicle and trailer frames.

Key Benefits:

• Strong yet lightweight.
• Easy to fabricate and install.
• Can be welded, bolted, or riveted.
• Reliable for long spans and vertical supports.

Steel Tube

Steel tubing is a hollow structural section (HSS) with a cross-section that varies based on the desired shape (e.g., square, rectangle, or round). It combines the strength of solid steel with the efficiency of reduced weight, making it ideal for frameworks that require rigid support and clean lines.

Mainline Metals supplies tubes in various wall thicknesses, lengths, and grades, tailored to your design and load requirements.

Common Applications:

• Structural framing and supports.
• Fencing and railing systems.
• Furniture and display fixtures.
• Machinery bases and enclosures.
• Construction and agricultural equipment.

Key Benefits:

• Excellent strength-to-weight ratio.
• Uniform shape for consistent fabrication.
• Resists twisting and bending.
• Clean, modern aesthetic for visible applications.

Wide Flange Beam

Often referred to as an I-beam or H-beam, the wide flange beam is a staple in modern construction. Its flanged edges and central web provide maximum load-bearing capacity while minimizing material weight, making it essential for large-scale structural support.

Wide flange beams are used in steel frame construction, bridge supports, and heavy equipment, offering long spans and resistance to bending or buckling.

Common Applications:

• Building columns and beams.
• Bridges and overpasses.
• Industrial mezzanines and platforms.
• Equipment support frames.
• Infrastructure projects.

Key Benefits:

• Exceptional structural strength.
• Efficient for long-span applications.
• Supports heavy vertical and horizontal loads.
• Widely used in construction and engineering.

Prime, Secondary and Excess Steel: What are the Differences?

At Mainline Metals, we offer prime, excess, and secondary steel to meet a wide range of performance and budget requirements. Here’s a quick breakdown of what each category means:

Prime Steel

This is first-quality steel produced to strict mill specifications with full certifications and mill test reports (MTRs). It’s ideal for critical applications where quality and consistency are non-negotiable.

Secondary Steel

This steel may have minor imperfections like surface blemishes, gauge variation, or edge wave, but it’s still structurally sound. It’s a budget-friendly solution for projects that don’t require perfect specs or cosmetic appearance.

Excess Steel

Also called surplus or overrun steel, excess steel comes from unused inventory from mills or service centers. It’s still top-quality material, but available at a discounted price, making it a smart option for non-critical or cost-sensitive jobs.

Each type has its place, and our team can help determine which option best suits your application—whether you’re optimizing for performance, cost, or a bit of both.

Why Choose Mainline Metals for Your Flat Rolled Steel Needs

With many steel suppliers in the market, what sets Mainline Metals apart is our unwavering commitment to service, relationships, and reliability.

Mainline Metals was built on the values of hard work, integrity, and long-standing partnerships, principles that continue to guide our business today. Our team, from warehouse staff to senior leadership, is available day or night to support your operation and keep your supply chain running smoothly.

Backed by decades of industry experience, a diverse and well-managed inventory, and a responsive service model, Mainline Metals is equipped to be your trusted source, whether you need a steel coil or steel sheet supplier, a steel plate distributor, or a cost-effective solution for excess galvanized material.

Partner with Mainline Metals for Your Flat Rolled Steel Needs

Flat rolled steel is more than just material. It’s a critical component in meeting your project deadlines, maintaining production schedules, and delivering consistent results. At Mainline Metals, we understand the importance of reliable supply and responsive support, and we’re committed to helping you source the steel products that best suit your requirements.

Whether you’re looking for prime, excess, or secondary flat rolled steel, our experienced team is ready to assist with inventory availability, pricing, and logistics.

Contact us today to learn more about our full range of flat rolled steel products and discover how we can help support your operation.

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