How to Bend Sheet Metal : The Basics

Whether you run your own auto body shop or fix up cars in your free time, knowing the basics of metal bending, forming, and shaping is a must-have skill.

Automotive metal shaping comes into play in many types of typical car fixes, from fixing bumpers to smoothing out door panels, to taking care of minor bumps and bruises during a car’s life, you can be sure that at some point or another, you’ll need to work with metal.

Obviously, the best way to learn about this skill is to do it -- working with sheets of metal to understand how they move and bend in various ways. But short of practical experience, it can be helpful for professional mechanics and auto hobbyists alike to familiarize themselves with some of the basics before diving in.

Below we will walk through some of the first most important things to know when you are getting started in working with metal shaping and forming, as well as some tools you should have on hand, too.

Metal Shaping and Forming

When it comes to metal shaping and forming for automotive purposes, there are a few general categories of work: sheet metal (large and small pieces), pipe or tube bending, and metal shrinking and stretching.

Depending on what kind of job you are doing, you may require different tools at the ready, so we will explain which ones you should have on hand at the shop or at home.

Sheet metal -- shaping big pieces

Sometimes a piece of a vehicle can get damaged in an accident, can rust due to extreme weather conditions, or erode due to years of use.

In these cases, when a large portion of the car requires fixing, you will need to use bigger pieces of sheet metal to take care of the issue.

What to shape - There are several parts of automobiles that might require using a large piece of sheet metal. Among others, the most typical parts of the car that will require this are fenders, door panels, and hoods.
Tools needed - For each project you are working on, you’ll likely find that a combination of different tools are necessary. We’ve laid out a few must-haves for each category of project, but these lists are not exhaustive. When you’re working with large pieces of sheet metal, there are several tools you should have on hand:

Vise-grip locking tool: for clamping and holding everything in place
Slip or bead roll: strengthens the sheet metal and/or adds a design
Shear: for cutting rough shapes out of medium to large pieces of sheet metal
Wheel anvils: shapes metal for a professional result

Sheet metal -- shaping small pieces

When you are working on smaller fixes like dings and dents, it is not necessary to pull out the big guns with large pieces of sheet metal. Instead, these issues can often be rectified by shaping small pieces.

Tools needed - You may find that these kinds of jobs are better done by hand. In such cases, you’ll want to have hand tools at the ready:

Mallet: for banging out small dents
Body Hammers: for tapping out dings
Dollies: backing plates for hammer blows

Pipe/tubing bend

Not all parts of a car are so simply repaired -- sometimes you might need to shape metal to fix pipes or tubes on the vehicle, such as an exhaust pipe or valve. In these cases, you will likely need some tools that can help you get down to the smallest of details.

Tools needed - When working on bending pipes or tubing, a few tools are available that can help you get the job done:

Bullet pipe bender: flares and expands the metal
Manual pipe bender: same as above, by hand
Pipe bending pliers: for fine tuning the pipe formation and angle

Metal shrinking and stretching

For more cosmetic fixes from slightly stretched or damaged areas, rather than replacing the metal, you might consider heat shrinking and/or stretching. While not always possible, in some instances you can avoid extra costs using this method.

Tools needed - When doing these kinds of fixes, you will want to have a machine to help you do the job well:

Shrinker/Stretcher: forms complex desired shape

Some Guidelines for Working With Sheet Metal

As we mentioned above, the best way to understand the steps of shaping sheet metal is to do it with the guidance of a teacher or more experienced mechanic. However, here are a few guidelines to follow as you begin working with metal in your job or personal garage:

Make sure that you have all the materials that you need to get started. Remember the smaller extras that you’ll need, such as a marker, ruler, protractor and the like.
Take measurements of the sheet metal, material thickness, parts, and any other relevant items in order to get a better sense of the space you’ll be working within.
Figure out the bend allowance for the metal you’re using. You can calculate this number by hand, an online calculator, or referencing a chart like this one.
Mark your bending lines with the marker, and use the bend allowance measurement to draw the second bend line.
Cut your sheet metal to the right size, making sure to smooth out and file down any nicks and rough edges that can damage the metal.
Place the forms in the vice grip or machine you are using, and either hammer out or run the tool to get the desired bend or form you’re looking for.

Again, this process will vary depending on your particular project, but having a sense of what it might look like to get started will help as you dive into practice.

Get Started With Metal Bending and Forming

If you plan on either working (or playing!) in the automotive industry, you will likely need to learn some skills around metal formation and manipulation. Given that both normal wear and tear along with vehicular accidents often necessitate knowledge of bending and forming sheet metal.

Even for the most skilled auto enthusiast, the right tools on hand are important to have. While some machines can be helpful along the way, if you do much of your work by hand, knowing you have the right tools in your shop to complete whatever project that comes your way.

Here at Auto Body Toolmart, we understand how important it is to be prepared with both the knowledge and equipment required to get the job done. That’s why we offer a wide selection of premium metal shaping tools from brands you know and trust.