Expanded metal is one of the most versatile products in the yard, and one of the most misunderstood. Whether you're building a mezzanine walkway, a security screen, a machine guard, or a set of trailer ramps, the right sheet of expanded metal does the job of heavier, pricier materials at a fraction of the weight. The trick is knowing what to order.

This guide breaks down how expanded metal is made, the difference between standard and flattened, when you need heavier expanded grating, and how to spec the right sheet the first time.

What Is Expanded Metal?

Expanded metal starts as a single flat sheet or coil. A machine slits the metal and stretches it in one pass, opening up a pattern of diamond-shaped holes. Nothing is punched out or removed, so there's no wasted material and no scrap.

That process is why expanded metal punches above its weight. Stretching the sheet work-hardens the strands and puts them on an angle, so a finished sheet is stiffer and stronger than the flat stock it came from. Because it's all one piece, there are no welds, joints, or fasteners to rust loose or pop under load. It won't unravel like woven wire mesh if you cut into it, and the open diamonds shed water, dirt, and debris instead of trapping them.

Standard vs. Flattened Expanded Metal

The first choice you'll make is standard or flattened. This matters more than most buyers realize.

Standard (raised) expanded metal comes straight off the machine with the strands and knuckles left at an angle. Those raised diamonds give you a naturally slip-resistant, grippy surface, which is exactly what you want on a walkway, ramp, or step. It's also the stronger and stiffer of the two.
Flattened expanded metal is standard mesh that's been run through a cold roller to press the strands flush. The result is smoother, flatter, and slightly wider, with a cleaner look. It's easier to weld into a frame, sits flat against a surface, and is the better pick for shelving, cabinet fronts, fencing panels, and anywhere appearance or a flush face matters. You give up a little rigidity and grip for that flat surface.

Rule of thumb: if people or equipment will walk or roll across it, lean toward standard. If it's a panel, screen, or infill, flattened usually wins.

Expanded Grating: When You Need to Walk On It

For platforms, catwalks, and stair treads, you step up to heavy expanded grating - thick, raised expanded metal built to carry real load. It's specified by weight per square foot, so a heavier number means a beefier, higher-capacity sheet.

Here's what we stock at Ram Steelco as an example of the range:

6.25 lb. carbon steel expanded grating (hot-rolled, raised profile) with a 0.813″ x 3.380″ diamond, in sheet sizes up to 48″ x 96″, 48″ x 144″, 72″ x 96″, and 72″ x 144″.
3.30 lb. stainless steel expanded grating in a raised profile, available in 304L or 316L, in 48″ x 120″ sheets.

The self-draining diamonds make expanded grating a smart choice for wet, outdoor Oregon work. Rain runs straight through instead of pooling, so you get safer footing on decks, ramps, and platforms through the rainy season.

How Expanded Metal Is Sized and Specified

A few terms will get you the exact sheet you need:

SWD (Short Way of Diamond) is the short distance across a diamond opening; LWD (Long Way of Diamond) is the long distance. Together they define the size and shape of the openings.
Gauge refers to the thickness of the original sheet before it was expanded. A heavier gauge means a stronger, more rigid finished product.
Strand width is the amount of metal between the openings. Wider strands add strength; narrower strands open up more airflow and visibility.

Lighter expanded metal is commonly called out by its SWD fraction and gauge - for example, 3/4 #9 means a 3/4″ short-way diamond made from 9-gauge sheet. Heavy expanded grating, like the products above, is called out by weight per square foot instead. If you're not sure which designation fits your job, tell us what you're building and we'll match it.

Choosing the Right Material

Expanded metal comes in several materials, and in the wet Pacific Northwest, corrosion resistance should drive the decision:

Hot-rolled carbon steel is the strongest and most economical option, and the standard choice for structural and industrial work. For outdoor use, plan to paint, powder-coat, or galvanize it to hold off rust.
Stainless steel (304L or 316L) resists corrosion without any coating. Go with 316L for coastal or chemical exposure. Not sure which grade? Our guide on 304 vs. 316 stainless breaks it down.
Aluminum is lightweight, naturally corrosion-resistant, and easy to handle - ideal where weight matters or a sheet needs to move. See our aluminum buyer's guide for more.

If you're leaning toward coated carbon steel for the savings, our galvanized steel guide covers how coatings protect steel in a wet climate.

Common Uses for Expanded Metal

Expanded metal shows up almost everywhere once you start looking:

Walkways, catwalks, mezzanine floors, and stair treads using heavier expanded grating
Security screens, window and door guards, gates, and fencing where you want to see and let air through while keeping people out
Machine guards and equipment enclosures that need airflow and visibility for safety
Trailer floors, ramps, and running boards that have to shed mud and grip
Shelving, racks, and lockers where flattened mesh keeps a clean, flat face
Sunscreens, facades, and railing infill panels for architectural and decorative work

Expanded Metal vs. Bar Grating

These get confused often. Expanded metal is a single stretched sheet - lighter, more economical, self-draining, and a great fit for walkways, screens, guards, and platforms with foot traffic. Welded bar grating is built from separate bearing bars locked together and is aimed at the heaviest industrial and vehicular point loads.

For the large majority of walkway, platform, screen, and enclosure jobs, expanded grating gives you the strength and safety you need at a lower cost and lighter weight. If you're carrying forklifts or trucks across it, that's when a heavier bar-grating system makes sense.

Getting It Cut to Size

Expanded metal rarely goes in as a full sheet. We can process it to your dimensions in-house so it drops right into your project:

Shearing and saw cutting for clean, square panels
Laser cutting, Hy-Def plasma, and flame cutting for custom shapes, notches, and openings
Forming and rolling to bend panels to your profile
DXF/PDF conversion to turn your drawing into a cut file

Send us a print or a rough sketch and we'll handle the rest. Need it fast? We offer free next-day delivery across the Willamette Valley, mid-Oregon coast, and surrounding areas.

Why Buy Expanded Metal Locally

Real stock on the shelf in carbon steel, stainless, and aluminum, so you're not waiting on a mill order
Cut-to-size processing under one roof, so you get finished panels, not just raw sheets
Free next-day delivery across our Oregon service area, or fast pickup at the warehouse
Experienced sales staff who'll help you spec the right material, gauge, and pattern - locally owned and operated since 1938

Get a Quote

Building something with expanded metal or grating? Tell us what you need and we'll get you a number.

Request a quick quote online with your sizes and material
Browse our stock, like this 6.25 lb. carbon steel expanded grating or 3.30 lb. stainless expanded grating
Call us at 503.588.1311 or contact our sales team - we'll help you get the right sheet the first time

Ram Steelco is a locally owned steel and metals supplier in Salem, Oregon, serving contractors, fabricators, farmers, and manufacturers since 1938 with carbon steel, stainless, aluminum, in-house processing, and free next-day delivery across Oregon.