Corten steel edging is widely popular in modern landscaping because it provides a sturdy, neat boundary for lawns, planting beds, paths, gravel areas, and retaining structures. Its weathered rust also adds a natural architectural aesthetic to the garden. However, when standard-length edging does not meet your project’s needs, you may need to cut the weathering steel edging to the desired length, angle, or curve.
The correct cutting method depends primarily on the edging’s thickness, the shape to be cut, and the tools available. Thinner weathering steel edging can be cut with heavy-duty shears, while edging that is 2–3 millimeters thick is typically better suited for a hacksaw or angle grinder. Regardless of the tool used, secure clamping, precise marking, appropriate personal protective equipment, and careful deburring are essential.
This guide will explain in detail how to safely and accurately cut weathering steel edging borders, covering topics such as which tools to use, how to make straight and curved cuts, and how to prepare the cut edges for installation.
The correct cutting method depends primarily on the edging’s thickness, the shape to be cut, and the tools available. Thinner weathering steel edging can be cut with heavy-duty shears, while edging that is 2–3 millimeters thick is typically better suited for a hacksaw or angle grinder. Regardless of the tool used, secure clamping, precise marking, appropriate personal protective equipment, and careful deburring are essential.
This guide will explain in detail how to safely and accurately cut weathering steel edging borders, covering topics such as which tools to use, how to make straight and curved cuts, and how to prepare the cut edges for installation.
1. Quick Answer
Most Common Applications
Corten steel landscape edging (Corten steel conforming to ASTM A606-4 or ASTM A588 standards) is cut on-site during garden construction to trim lawn edges, secure gravel paths, build raised flower beds, and create neat transitions between planting areas.
Recommended Tools by Thickness
► 18 gauge and below (1.2 mm): Aviation-grade shears or heavy-duty hand shears.
► 16 to 14 gauge (1.5 mm to 2.0 mm): Hacksaw, reciprocating saw with a bi-metal blade, or notcher.
► 2.0 mm to 3.0 mm (1/8 inch): A 4.5-inch angle grinder equipped with a 1.0 mm ultra-thin abrasive cutting disc, or a circular saw designed for cutting metal.
► Over 3.0 mm (3/16 inch to 1/4 inch thick steel plate): An angle grinder, plasma cutter, or oxy-acetylene cutter.
Key Safety Precautions
Be sure to wear ANSI-certified safety goggles, heavy-duty layered leather work gloves, long-sleeved clothing, and ear protection. Before cutting, securely clamp the metal strip to a sturdy workbench using C-clamps or rod clamps to prevent kickback, metal jamming, or severe blade vibration.
2. Understand Corten Steel Edging
Product Overview
Weathering steel edging is a high-strength, low-alloy steel specifically designed for outdoor hardscape applications. Weathering steel was originally developed to eliminate the need for painting or chemical sealing; when exposed to the outdoor environment, its surface forms a protective layer of iron oxide rust.
This alloy composition gives Corten steel a tensile strength (485 MPa vs. 400 MPa) and yield strength (345 MPa vs. 250 MPa) higher than those of standard carbon steel, making it significantly more difficult to cut.
Typical Thicknesses
Landscape edging is primarily divided into four thickness grades:
► Light-duty residential: 18 gauge (1.2 mm) — Offers good flexibility, is easy to shape by hand, and can form tight curves.
► Standard residential: 14 gauge (2.0 mm) — Maintains straight lines while also allowing for bending into large arcs.
► Heavy-duty commercial: 1/8 inch (3.0 mm or 11 gauge) — Suitable for rigid structural edging in public parks with high foot traffic and retaining walls.
► Architectural steel plate: 3/16 inch to 1/4 inch (4.5 mm to 6.0 mm) — Heavy-duty structural steel plate used for retaining walls and stair treads.
Why Extra Caution Is Required When Cutting
Because weathering steel contains an alloy of chromium, copper, and nickel, it work-hardens more quickly than ordinary low-carbon steel when subjected to heat generated by friction. Using a dull saw blade, rotating a grinding wheel without applying steady pressure, or forcing the use of manual shears can cause vitrification on the metal surface, which rapidly dulls the tool and leaves sharp, jagged edges that may cause injury.
3. Choose the Right Tools
Shears for Thin Edge Strips
Straight-cut aviation shears are ideal for working with thin, 18-gauge (1.2 mm) flexible edging. Choose blades made of chrome-molybdenum steel using a drop-forged process; their micro-serrated design securely grips smooth metal sheets and prevents slippage.
Hacksaws for Medium-to-Thick Metal
A 12-inch rigid bow saw equipped with a high-speed steel (HSS) or bimetal 24 TPI (teeth per inch) blade can easily cut No. 16 to No. 14 (1.5 mm to 2.0 mm) metal. Ensure the blade tension is set high (over 20,000 PSI) to prevent the blade from bending during cutting.
Angle Grinders for Thick Sections
A 4.5-inch (115 mm) angle grinder operating at 10,000–12,000 RPM is the standard construction tool for cutting weathering steel edging strips thicker than 2.0 mm. Use the angle grinder in conjunction with ultra-thin (1.0 mm to 1.2 mm) Type 27 or Type 41 reinforced abrasive cutting discs designed specifically for steel and stainless steel (INOX).
Deburring with a File
Immediately after cutting, use a 10-inch single-edged file or a 40-grit/80-grit flap wheel mounted on an angle grinder to smooth out any dangerous metal burrs.
Clamping and Support
When cutting, use heavy-duty cast-iron C-clamps or quick-release steel bar clamps to secure the weathering steel strip flat against a sturdy workbench, sawhorse, or wooden backing board.
Measuring and Marking Tools
High-contrast white acrylic oil-based markers, silver welder’s pencils, or carbide scribers can clearly mark cutting layout lines on the original gray mill scale or brown rust.
4. Prepare for Cutting
Measuring Length
Use a flexible steel tape measure to measure the perimeter of the landscape flower bed. When joining interlocking Corten garden edging, allow for a 25-millimeter to 50-millimeter overlap at the end clips or slip joints.
Marking the Cut Lines
Place a steel square across the edging strip and mark a vertical line at a 90° angle. For bevel cuts, mark the precise bevel angle (45° at right angles) on both the top edge and the vertical face of the edging strip.
Securely Clamp
Position the marked cutting line approximately 10 to 20 millimeters outside the edge of the workbench or support block to minimize vibration. Secure the workpiece by attaching at least two heavy-duty clamps near the cutting line.
Set Up the Work Area
Clear dry leaves, grass clippings, sawdust, and synthetic materials from a 5-meter radius around the work area to prevent sparks from high-temperature grinders from causing a fire.
Wear Safety Equipment
Put on all personal protective equipment (PPE) before plugging in power tools or picking up metal shears.
5. Safety First
Wear Safety Goggles and Gloves
Wear safety goggles that comply with the ANSI Z87.1 standard under your full-face mask to protect against metal debris and fragments from breaking cutting discs. Wear thick, layered cowhide gloves to protect your hands from razor-sharp cut edges.
Use Hearing Protection
Noise levels generated by an angle grinder cutting structural steel may exceed 105 dBA. Wear earplugs (NRR 25+) or noise-canceling earmuffs to prevent hearing loss.
Secure the Edge Strip
When cutting with a power tool, never hold the metal edging in place with your hands or feet. If the blade becomes jammed in the cut, the high torque of the angle grinder or reciprocating saw may fling the unsecured edge strip toward the operator.
Keep Both Hands Away from Hazardous Areas
Both hands should grip the power tool’s handles and remain behind the guard. Never reach under the cutting plane while the saw blade or grinding wheel is in operation.
Work in a Well-Ventilated Area
Grinding weathering steel releases fine iron oxide, chromium, and manganese dust into the air. Be sure to cut outdoors or in a well-ventilated workshop, and wear an N95 or P100 particulate respirator.
6. Cut Straight Lines
Secure Clamping
Secure the weathering steel border to a flat wooden support board. Supporting the bottom of the thin metal sheet reduces vibration and noise and prevents the saw blade from wobbling.
Align the Tool with the Cut Line
Align the saw blade or grinding wheel with the marked cut line on the scrap side. Keeping the mark intact ensures that the finished steel strip matches the measured dimensions.
Cut Slowly
Start the power tool and wait until it reaches full speed before making contact with the edge of the steel. Lightly score the metal surface along the marked path to form an initial guide groove, then deepen the cut.
Let the Tool Do the Work
Apply gentle and even forward pressure. Forcing the angle grinder or saw blade forward can cause overheating, dull the cutting teeth, accelerate grinding wheel wear, and potentially deform the thin metal strip.
Deburring
Immediately after the cut piece breaks away, use a file or a flap wheel to smooth both sides of the cut to remove razor-sharp metal burrs and sharp edges.
7. Cut Curves and Angles
Marking with a Template
When making curved cuts, create a template out of cardboard or plywood that matches the radius of the flower bed. Using a silver welder’s pencil or a scriber, trace the outline along the edge of the template onto the Corten lawn edging.
Use Metal Shears for Gentle Curves
For thin weathering steel (1.2 mm), use left-cutting (red handle) or right-cutting (green handle) aviation shears to cut along wide curves, preventing the scrap strip from twisting or warping.
Use an angle grinder for sharp turns
For thicker strips (2.0 mm to 3.0 mm), use an angle grinder to make a series of short, straight tangential cuts along the outer edge of the curve to cut a small-radius curve.
Cutting in sections
When creating small-angle miter joints or grooved ground anchors, first cut relief grooves into the scrap material. Removing small rectangular sections prevents the cutting blade from getting stuck in deep miter grooves.
8. Deburr and Finish
Removing Burrs
Power cutting tools leave thin, sharp ridges of molten metal (known as slag or burrs) along the bottom edge of the cut. Before filing, use a cold chisel or steel hammer to knock off any large burrs.
Smooth Sharp Edges
Hold a coarse single-edged file against the cut edge at a 45° angle and push it forward in long, steady strokes. Slightly chamfer the top and bottom corners to create a safe, rounded edge profile.
Check for Rough Spots
Wear gloves and gently run your fingers along the entire cut edge to check for hidden burrs, snagging points, or sharp metal edges.
Remove Metal Debris
Use a dry wire brush or work cloth to brush away steel grinding dust, metal shavings, and abrasive particles. Removing fine iron dust prevents temporary rust stains from appearing on adjacent concrete or stone surfaces.
9. Tool by Thickness
18 Gauge and Below: Tin Snips
► Material Thickness: ≤ 1.2 mm
► Recommended Tools: Eccentric aviation shears or a manual edge nipper.
► Pro Tip: Keep the shears’ jaws perpendicular to the sheet metal. Avoid closing the jaws completely at the end of each cut to prevent tearing the metal borders.
16 Gauge: Heavy-duty Shears or Hacksaw
► Material thickness: 1.5 mm
► Recommended tools: Bimetal hacksaw (24 TPI), electric shears, or a reciprocating saw equipped with a fine-tooth metal blade.
► Pro tip: Apply a drop of cutting oil along the score line to cool the saw teeth and reduce tool wear.
2–3 mm: Hacksaw or Angle Grinder
► Material thickness: 2.0 mm to 3.0 mm
► Recommended tools: 4.5-inch angle grinder (1.0 mm INOX cutting disc) or a circular metal-cutting saw equipped with a carbide-tipped blade.
► Pro tip: Maintain a high grinding wheel speed and avoid twisting the angle grinder body within the cut.
Over 3 mm: Angle Grinder
► Material thickness: >3.0 mm (1/8 inch to 1/4 inch)
► Recommended tools: Angle grinder with a heavy-duty grinding wheel, plasma cutter, or oxy-fuel cutting torch.
► Pro tip: When cutting thick structural steel plates, make multiple shallow cuts rather than attempting a single deep cut.
10. Tips for Clean Cuts
1. Mark the Layout Lines with a White Permanent Marker
High-contrast markings remain clearly visible even amid the sparks and dust generated during sanding.
Please use a bright white permanent marker or a silver welder’s pencil, rather than a regular graphite pencil. To ensure accuracy, use a steel ruler to draw straight lines.
2. Secure the Steel Near the Cutting Line with C-Clamps
A secure clamp eliminates blade wobble and tool jamming
Clamp the edge strip to a thick wooden support board, positioning the clamp 20 to 50 millimeters from the marked cutting line to minimize vibration.
3. Maintain High RPM and Steady Feed Pressure
A constant RPM prevents metal hardening and tool jamming
Allow the cutting wheel to reach full speed before making contact with the metal. Move the tool smoothly along the cutting line; never force the blade.
4. Chamfer Both Cutting Edges Using an 80-grit Flap Wheel
Chamfering creates a smooth, safe architectural finish
Immediately sand the cut edges with an 80-grit flap wheel or a hand file held at a 45-degree angle to remove sharp burrs.
11. After Cutting
Clean Up Metal Shavings
Sweep up all metal shavings, sawdust, and grinding wheel dust from the workbench and lawn. Residual iron dust will rust rapidly upon contact with moisture, leaving orange rust stains on nearby stone pavers.
Check the Edges
Ensure that the cut edges are straight, vertical, and smooth. Verify that the connecting clip slots and mounting pin holes are intact and properly aligned.
Repair Rough Areas
If you accidentally create dents or scratches on the surface of the pre-oxidized Corten steel strip during cutting, spray the exposed metal surface with a mild solution of saltwater and hydrogen peroxide to accelerate the formation of a rust passivation layer.
Prepare for Installation
Lay the cut garden edging along the perimeter of the flower bed. Before driving the anchor stakes into the ground, double-check the fit, overlap spacing, and alignment of the beveled edges.
12. FAQs
Q1: Can I Cut It Myself?
Yes. DIY enthusiasts can easily cut weathering steel landscape edging using basic tools, such as aviation-grade shears for thin-gauge material or a 4.5-inch angle grinder for standard commercial thicknesses.
Q2: What is the Best Tool?
A 4.5-inch angle grinder equipped with a 1.0-millimeter ultra-thin INOX abrasive cutting disc offers the best combination of cutting speed, precision, and versatility for all edging thicknesses.
Q3: Can Metal Shears Be Used?
Scissor-style metal shears can cut lighter 18-gauge (1.2-millimeter) weathering steel edging border. However, they are not recommended for cutting 16-gauge (1.5 mm) or thicker metal.
Q4: How do I cut a straight line?
Use a steel ruler to mark a clear line, clamp the metal strip securely to a flat work surface to prevent vibration, and then slowly guide the angle grinder along the marked layout line to make the cut.
Q5: How Do I Cut Curves?
When cutting thin metal, use curved aviation shears. For thick metal, use an angle grinder to make a series of short, straight cuts along the marked curve, then sand the edges smooth with a 40-grit flap disc to create a smooth curve.
Conclusion: Summary of Best Practices
The key to clean and precise cutting of Corten landscape metal edging lies in proper planning, the right tools, secure clamping, and thorough edge finishing. By selecting the appropriate cutting tool based on the metal’s thickness, securing the workpiece flat, and maintaining a steady feed rate, you can achieve clean, precise cuts in any landscape design.
Matching tool power to metal thickness is crucial. While thin 18-gauge edging strips can be quickly cut with hand shears, thicker 14- to 11-gauge commercial edging strips require a 4.5-inch angle grinder equipped with a thin INOX cutting disc to ensure a smooth cut without damaging the tool.
Safety and surface finishing are just as important as the cutting process itself. Be sure to always wear a full set of protective gear to guard against high-speed flying sparks and airborne metal dust; after each cut, use a file to remove sharp burrs, ensuring a safe and durable landscape installation.
