How a Sheet Metal Brake Works (And Your Alternatives)

Working effectively with sheet metal as a roofing material hinges on two crucial elements: expertise and the right tools. You can have all the necessary tools and equipment, but without experience, success is unlikely. Conversely, an experienced sheet metal roofer without the right tools is like a fish out of water.

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This principle is true in many industries, particularly those requiring skilled labor, such as machining, engineering, or trades like sheet metal roofing.

A sheet metal worker’s role involves cutting, shaping, and forming panels of metal—often stainless steel, aluminum, or copper—so that they can be secured and seamed into a functional, durable metal roof. Numerous specialized tools assist in this process.

One essential tool is the sheet metal brake. Contrary to what the name might imply, sheet metal brakes are not used to slow down metal sheets. These tools are designed for making precise bends and folds, most commonly at the edges of metal sheets.

Generally, sheet metal brakes are employed to shape large sections of metal, which can then be further refined and installed by roofers. Consequently, most metal brakes are sizeable, freestanding machines. Here’s an overview of the different types of sheet metal brakes and how they function.

Types of Sheet Metal Brakes and Their Mechanisms

While a brake is designed to bend metal, there’s a significant variety in their types and capabilities. Some brakes only allow for basic creases and folds at the sheet's edges, whereas others can manage more complex bends. Below are some of the most common types of metal brakes:

• Cornice Brake: These brakes are designed for simple bends and folds on large metal sheets. The metal sheet is clamped to a stationary surface and bent using a bending leaf. Although effective for making precise bends at the edges, this method is limited in the variety of bends it can produce.

• Box and Pan Brake (Finger Brake): These brakes enable more complex bends and shapes, including box and pan forms. The adjustable 'fingers' allow for versatility in the shapes produced.

Using a box and pan brake, complex shapes like boxes and steps can be created in metal sheets. This brake is versatile and suitable for projects requiring intricate bends.

• Press Brake: More complex than cornice or finger brakes, press brakes utilize a punch and die setup to achieve intricate bends. They may operate mechanically, hydraulically, or pneumatically.

Press brakes utilize different types of dies such as V dies for simple bends, 90-degree dies for right angles, and more specialized hemming and curling dies. These features make press brakes highly versatile.

Despite their power, versatility, and ability to produce swift, precise bends, most sheet metal brakes are large, heavy, and non-portable. Hence, while effective, they may not be the most convenient tools for itinerant roofers.

Sheet Metal Brakes: Not the Ultimate Solution

For traveling sheet metal roofers, there are more convenient and cost-effective alternatives that offer similar utility. While these tools may differ in mechanical action and size, they are highly useful.

Sheet Metal Benders

Besides brakes, roofers may use tools like sheet metal roll benders. These benders are smaller and lighter, making them portable and practical for on-site work.

Portable benders like the Stortz Pocket Bender are advantageous for roofers needing bending tools on the job site. This compact device can fit in a tool belt, making precise bends effortless.

We offer various sheet metal benders under our brand and from other reputable manufacturers, like Wuko and Freund. These tools bridge the gap between large brakes and smaller, more portable options.

For more complex bends, tools like the Stortz Perfect Bender S-150 can bend up to 110 degrees without damaging painted surfaces.

While ideal for edge bends, rolling benders also make it easy to start eaves and seams, effectively functioning as portable sheet metal brakes. For even finer precision, robust sheet metal pliers can be invaluable.

Sheet Metal Pliers

Though not strictly bending tools, sheet metal pliers are versatile and practical. They can start or finish seams, produce bends, and manipulate sheet metal with ease.

For example, Steadman Offset Tongs are excellent for gripping and arranging sheet metal, making bends up to 1 inch deep along edges.

Tools like the Stortz 90-degree Seaming Pliers provide precise performance for creating hard-to-reach bends and starting seams.

Specialized tools like Stubai Double Seaming Pliers are engineered for creating mechanically locked seams in difficult spots. Their unique design ensures efficient seam locking.

General-purpose tongs and pliers can also be used for rough adjustments and bends, especially in tight spaces where other tools may not fit.

Cutting Tools and Other Essentials

Besides brakes, benders, and pliers, other essential tools are crucial for sheet metal workers.

• Cutting tools: Necessary for shaping metal, tools like tin snips and nibblers offer precise cuts without edge deformation.
• Decoilers: Used to manage and uncoil heavy sheet metal rolls efficiently.
• Gutter tools: Essential for creating effective gutter systems to manage rainwater runoff.
• Marking tools: Critical for ensuring accurate cuts and bends by allowing precise measurements.

If you need more information about the tools used by sheet metal roofers or are looking for a new bender or pair of aviation snips, you're in the right place. For over a century, Stortz & Son has been the trusted resource for tools and expert advice.

Explore our offerings online or contact us for recommendations at 888-847-3456. We're here to help!

Table of Contents

What is Sheet Metal Bending?

CNC sheet metal bending is a highly versatile process for producing various part geometries without extensive tooling. It's particularly useful for low to medium volume production due to its speed, repeatability, and automation capabilities. This makes it an attractive option where other production costs are high.

Bending techniques are indispensable for product developers, engineers, and businesses. Paired with laser cutting, bending can handle low to medium volume production efficiently.

Understanding the possibilities with sheet metal bending during the design phase is crucial. Bending allows for creativity in shaping and designing parts, often reducing costs and improving strength by using single material pieces instead of multiple joined parts.

This guide provides an overview of primary sheet metal bending processes, their advantages and disadvantages, basic design considerations, and material selection information. It aims to equip you with the knowledge to discuss your products' fabrication with sheet metal manufacturers like us.

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Types of Sheet Metal Bending

There are multiple methods for bending sheet metal, but the primary ones are brake press bending and rolling. The chosen process depends on the material and part specifications.

Brake Press

A brake press is a time-honored tool in fabrication. It forms work pieces between two dies, accommodating materials from 0.5mm to 20mm thick due to its powerful hydraulic machinery.

Brake presses are categorized by tonnage and width. Tonnage refers to the maximum force the press can exert, while width specifies the maximum bend length. Brake press bending includes two main types: air bending and bottom bending.

Air Bending

Air bending involves a v-shaped bottom tool and a narrow, rounded top punching tool. The sheet metal is bent into shape, leaving a gap between the metal and the bottom tool. It's versatile and requires less pressure, allowing various bend angles with the same die.

Bottom Bending

Bottom bending uses a punch to push the sheet metal fully into a v-shaped die. It creates more accurate angles with less springback but requires different dies for each bend and more pressure.

For a detailed comparison, check our guide: Bottom Bending Vs Air Bending.

Rolling

When cylinders or curved parts are needed, sheet metal is rolled to the required curvature using a rolling machine. Rolling machines vary in size, accommodating different material thicknesses.

The most common rolling machines have three rolls. The top roll is moved closer to the bottom rolls, and the material passes through, obtaining a curved shape. Rolling compensates for springback by rolling to a slightly tighter radius than required.

Post-rolling, the bottom roller can be adjusted downwards to release the sheet metal, or the top end yoke can open as needed. Pre-bending may be required to ensure cylinder ends meet.

When to Use Sheet Metal Bending in Fabrication

Contact us to discuss your requirements for metal furniture panel bender. Our experienced sales team can help you identify the best options.

Sheet metal bending offers flexibility in metal types and thicknesses. It’s used in various industries, including automotive, appliances, furniture, and industrial equipment.

A wide range of metals, including steel, aluminum, copper, and titanium, can be bent. Sheet metal bending processes can handle materials as thick as 20mm.

Modern CNC machines that combine cutting and bending can produce complete parts from a single sheet, reducing costs and production times.

Sheet metal bending can be combined with other operations like fastening, threading, and boring, enhancing part versatility.

Our article on “Value Added Operations for Sheet Metal Components” provides more information.

Advantages

Speed of Manufacture - Automated CNC bending allows for quick sheet metal part production, even with 24/7 operations and minimal personnel.

Accuracy - Modern CNC machinery ensures high accuracy and repeatability, crucial for precision parts.

Reduced Post-Processing - Unlike other fabrication methods, bending often eliminates post-processing needs like grinding or straightening.

Less Weight - Efficient bending techniques can create strong, lightweight parts, enhancing in-use performance and reducing transport issues.

Low Cost and Minimal Tooling - CNC bending reduces labor costs and tooling needs, making it cost-effective with quicker lead times.

Reduction in Part Complexity - Bending often allows for single-piece part production, reducing errors and simplifying assembly.

Disadvantages

Despite its benefits, sheet metal bending has some drawbacks.

Thickness Limitations - Thicker materials have higher bend radii, restricting tight bends to thinner sections.

Need for Consistent Thickness - Parts are ideally designed with uniform thickness to simplify production.

Cost of Manufacturing - Better suited for low to medium volumes; high volumes may favor stamping for cost-efficiency.

Production Issues - Bending may cause marks, fractures, or distortions, and bends must be positioned to avoid slipping and ensure precision.

Sheet Metal Bending Compared to Other Fabrication Processes

Process comparison:

Process	Best Used for	Precision Level	Thickness (mm)	Custom Tooling Required	Minimum Order Quantity	Lead Time
Laser Cutting	Small to large parts with any geometry	± 0.10mm	0.5mm to 20.0mm	No	1 to 10,000 units	Less than 1 hour
CNC Sheet Bending	Small to large parts with straight angles	± 0.18mm	0.5mm to 20.0mm	No	1 to 10,000 units	Less than 1 hour
CNC Punching	Parts with multiple holes and embosses	± 0.12mm	0.5mm to 4.0mm*	Typically No	1 to 10,000 units	Less than 1 hour
Stamping	High-volume production with tight tolerances	± 0.05 to 0.10mm	0.5mm to 4.0mm*	Yes	≥5,000 units	25 to 40 days
Shearing	Thin material with simple geometry	± 0.50mm	0.5mm to 4.0mm*	No	1 to 10,000 units	Less than 1 hour

Table 2: Sheet Metal Bending Compared to Other Fabrication Processes

Materials Suitable for Bending

Almost all engineering materials in sheet form can be bent to some degree. However, different materials have different processing limitations due to inherent properties.

Sheet metal is commonly available in gauges ranging from 0.03mm to 7.62mm. Bending can be performed with these and thicker gauges.

Gauge is a traditional term still used, although many metals like steel are directly specified by thickness. Aluminum often retains imperial measurements.

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