How to Fabricate Sheet Metal Trim

By Adam Clark

Fabricating custom exterior trim on-site can help you create the perfect fit and finish. Tapco Tools sheet-metal brakes offer precision to create a high-quality look, and they’re versatile, efficient, durable, portable, and easy to use.

In addition, on-site trim fabrication using Tapco Tools brakes, accessories, and trim coil can help save money on the job site when material prices are volatile—and offer a way for professional contractors to bring in extra money.

We estimate crafting your own trim can save up to 36 percent of the cost of pre-made trim.

Plus, bending trim can take place off site and indoors, allowing contractors to work well past dark during winter months or to generate extra income.

Getting Started with a Brake

Tapco Tools offers robust training and customer support to help you get started using a brake. Here's a step-by-step guide to setting up the brake.

The 4 Most Basic Shapes of Trim Bends:

Some of the most common bends on a brake that can get you nearly anywhere you need to go are hemming an edge, a sill seam, simple (3/4”) step flashing, and tight (1/2”) step flashing.

J-Channel and L-Bends

Making a J-channel fir siding on a Tapco brake is straightforward, and creating a window head flashing is a very similar process.

Bending Bay Window Corner Posts

Often, installers will try to stretch a vinyl siding corner at a 22- or 45-degree bay window. Here’s a better solution.

Tapco Tools Accessories

Along with a range of brakes suitable for everything from small remodeling shops to commercial projects, a full line of accessories provides even more versatility.

Tapco Tape

As we saw demonstrated at the 2025 International Builders Show, the new Tapco Tape accessory allows users to measure from the brake anvil and with a 1.5" offset for easy Pro Cutoff calculations without using a standalone tape measure. The result is easier, faster, and more precise bending. Tapco Tape clamps quickly to the brake for easy installation; drilling holes in the brake is not required. When not in use, the Tape hinges up and out of the way; then simply swing it down for a measuring scale to achieve all bends and cut-off measurements. With the measuring accessory in place, there’s no need to mark material with a tape measure and pencil and then line up marks with the anvil. Plus, the accessory has material stops to make repeat bends more efficient. Tapco Tape can be used with the Max-I-Mum XL, PRO 14, PRO 19, Pro II, Pro III, Pro 2000, and Pro 50” Tapco Tools brake models.

Brake Buddy

The Brake Buddy allows you to elevate your on-site trim fabrication with more style and originality, including producing brickmold trim and decorative ribs in just seconds. Suitable for any Tapco Tools portable brake, the Brake Buddy features a measurement guide and quick-twist handle that provide for quick adjustments and simple, efficient operation.

Pro Cut Off

For cutting, the Pro Cut Off for Tapco Tools Pro Series brakes provides factory-quality, single-pass cuts of heavy-duty sheet metal, eliminating the need for utility knives and shears. It features an easy-adjust mechanism for versatility and an ergonomic grip for smooth operation.

 Learn More and Get Started

To learn more about getting started with a Tapco Tools brake, visit www.tapcotools.com. Along with a library of instruction manuals and how-to videos, the Tapco Tools team is available to answer questions and provide training and support. 

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Editor's Note: Adam Clark writes for Westlake Royal Building Products.