Simple Sheet Metal Brake: No Welding




As long as I can remember I've been building stuff. I think it's high time I shared these projects.

I love working with metal, but I've always struggled to get perfect 90° bends. Generally, I'll stick the piece to be bent in the vise and smack it around until it's bent. Since it almost always bends crooked, I end up rebending - and generally just making a mess of it.

For my next project I was going to need to bend some cardboard, which inspired me to first tackle a bending brake. Since I knew I would end up bending things much harder than cardboard in the future, I designed the brake to handle thin aluminum and steel.

Inspiration for the design came from several other DIY brakes, such as this one by Improbable Construct and one by the Youtuber JDCD Design. Since I don't have easy access to a welder (and also try to avoid welding as I'm not terribly great at it), I modified the design to make it weld-free.

Teacher Notes

Teachers! Did you use this instructable in your classroom?
Add a Teacher Note to share how you incorporated it into your lesson.

Step 1: What I Used

I used the following items for this build:

(1) 1/8" x 1.5" x 1.5" x 4' Steel Angle

(1) 1/8" x 2" x 3' Steel Plate

(1) 1/2" x 3' Steel Box

(1) 3/4" x 2.5" x 6' Dimensioned Board

(2) Hinges

(6) 1" x 5/16" Cap Screws

(6) 5/16" Lock Nuts

(10) 1" Drywall Screws

(2) 5/16" Wing Nuts

(2) 5/16" Washers

(2) 5/16" x 2.5" Carriage Bolts

(4) #10 x 1" Flat Head Machine Screws

(4) #10 Nuts

Wood Glue

Spray Paint Primer

Blue Spray Paint

I used the following tools for this build:

(Note that these links were made using my Amazon Affiliates account. I get a small commission if you buy anything on Amazon using my links. You pay the same price and are helping support me in sharing projects like these. Thanks!)

Hacksaw (not mine but similar):


Circular Saw:

Miter Saw:

Dremel (a newer version of mine):

Drill Bits (not mine, but I like these):

Forstner Bits (a larger set like mine):

Metal File (similar to mine):

Box Wrenches:

Allen Keys (not mine, but the same thing):

Step 2: Cut Stuff to Length

All of the metal and wood bits were first cut to length.

The 1.5" angle was cut in half to make two 2' pieces. This will be used to make the bending plate as well as the hold down clamp.

The 2" plate was cut to 2' in length. This will be used to form the smooth surface beneath the hold down clamp.

The 3/4" x 2.5" x 6' board was cut in half to make two 3' long boards. These boards will be glued together to form the base for the brake. The reason I used two thinner, dimensioned boards was that they were the thickest dimensioned boards I could find at Lowe's. 2x4's were not straight enough for this project and since I don't have a planer I typically buy my boards already planed.

Finally, the 1/2" x 3' box tube was cut in half to create two 1.5" pieces that will be used for the brake's handles.

Step 3: Cut Slots for Hinges in Angle

I wanted to use off-the-shelf hinges for my brake, but I didn't want to compromise on the location of the pivot point like many designs do. Ideally, the pivot point of the hinge should be directly inline with the bending line of the metal being bent.

In order to accomplish this, the hinges need to be located outside of the work area. In addition, the angle used for bending the metal needs to be slotted along it's bent edge to accommodate the barrel (the hingy part of the hinge) of the hinge. To maintain the strength of the angle, I chose to not run the slots the whole way to the end of the angle. By starting the slots at around 3/8" from the end of the angle, I was able to keep the two legs of the angle connected, which should help with the structural integrity of the angle. The hinge was laid on the angle to determine the length of these slots, which were made slightly longer than the hinge.

Cutting the slots proved to be a bit difficult since I did not run them to the end of the angle. I used my Dremel to help cut the flat spot to start the hacksaw in. After this it was simply a matter of cutting away the rest of the slot using the hacksaw. Since the hacksaw doesn't leave a particularly smooth (or straight) cut, I smoothed the slots out using a metal file.

Step 4: Cut Slots in Plate for Hinges

This step ended up being completely unnecessary as shall be shown, but I thought I would include it for completeness.

Next I cut slots in the steel plate to accommodate the barrels of the hinges.

Step 5: Drill Holes in Hold Down Angle

The second 2' piece of angle needs to be prepared for use as a hold-down clamp. Two points were marked 2.5" from each end of the angle. Since these points mark the location where holes need to be drilled, and since they lie on the bend in the angle, I created small flat spots at these points using a file.

I initially used a small (~1/8") drill bit to drill these holes since it fit nicely onto the flat spots. These holes were then enlarge to 5/16".

Step 6: Prepare Wood

This step also ended up being completely unnecessary, but here it is for completeness.

Since my initial design was to have the hinges lie beneath the flat plate, I cut recessed slots in the one 3' board to accommodate the hinges. I simply lowered the blade on my circular saw so that it protruded by 1/8" and made many cuts to create the groves.

I also needed to make angled cuts on the edge of the board to accommodate the barrels of the hinges. To do this, I locked the slides on my miter saw so that when the blade was fully brought down it would cut a 45° bevel on the edge of the board. Then I simply brought the blade down over and over again as I slid the board along the fence of the saw. I wasn't sure how this would work, but it ended up working out pretty well. Too bad I didn't need to do this.

Step 7: Attach Hinges to Board

The hinges were carefully aligned into the recesses on the board and clamped to hold their position. The centerline (pivot) of the hinges were aligned along the edge of the board. Once positioned, the hinges were carefully mounted to the board using drywall screws.

Step 8: Glue Boards Together

After the hinges were secured, their screws were partly removed as they protruded through the bottom of the board and would prevent the board from being glued to the second board. After coating the bottom of the first board with glue, I positioned it over the second board and re-tightened the hinge mounting screws. These screws held the boards together as the glue set up and no additional clamps were needed.

Step 9: Attach Plate

Recessed holes were drilled in the steel plate, which was then mounted above the hinges using four drywall screws. The edge of this plate was mounted flush with the edge of the board on the hinge side.

Step 10: Attach Bending Angle

Once the hinges and plate were attached to the board, the bending angle was temporarily clamped to the hinges to work out it's correct position. The edge of this bending angle needs to be perfectly inline with the pivot point of the hinges. The angle's edge will also be perfectly parallel to the edge of the steel plate and edge of the board. Once the position of the angle is correct, the holes in the hinges were used as guides for drilling 5/16" holes through the angle. The 1" cap screws were fitted through these holes, with the lock nuts being tightened onto them to secure the angle to the hinges.

Step 11: Design Correction

At this point, it became apparent that I had made a mistake in the original design of the brake. Ideally, the pivot point of the brake will lie perfectly inline with the bend line of the metal being bent. However, as I had designed the brake, the bending point was 1/8" above the pivot point of the hinge (see left side of drawing). The reason for this was that I had placed the steel plate over the hinges. If I were to place the steel plate at the same height as the hinges (inline with the surface of the hinges), the bend point and pivot point would be perfectly aligned (see right side of drawing). Since this was a relatively simple change to make, I decided to modify the brake.

Step 12: Trim Steel Plate

The main thing that needed to be changed for the new design was that the flat plate needed to be trimmed so that I would lie between the hinges. I simply cut the ends off the plate at the point where the slots for the hinges had ended. This plate ended up being around 17" long.

Step 13: Cut Slot for Cap Screw Heads

During the re-design I realized that I also needed to cut a slot in the side of the board to accommodate the heads of the cap screws used to mount the bending angle to the hinges. Without this slot, the cap head screws contact the board and keep the angle from fully opening. This is important because the bending angle needs to fully open to allow its face to be flush with the flat plate at the beginning of the bend. I cut a 3/8" deep slot in the side of the boards using the circular saw.

Step 14: Re-Attach Hinges and Plate

Since the hinges are now inline with the plate, I needed to flip the board so that the hinges were no longer recessed into the previously cut groves. I carefully positioned the flat plate and hinges and screwed the plate and hinges to the board. As seen in the last picture, the new groves for the cap screw heads allow the bending angle to fully open so that its face is flush with the plate. Also, since the pivot point is now inline with the bend point, the bending angle can be fully rotated to where it is flat against the plate.

Step 15: Notch the Hold Down

The ends of the hold down angle need to be notched to accommodate the hinges. I cut these notches using the hacksaw and cleaned them up with the metal file.

Step 16: Install Carriage Bolts

The carriage bolts are used to attach the hold down angle above the flat plate. I positioned the angle above the plate and used clamps to hold it in position. The front edge of the angle lies parallel to the edge of the plate, and is slightly inboard from the bend point. Using a 5/16" bit, I was angle to mark the position of the holes in the angle onto the hinges below. After the removing the angle, these marks were used to drill a small pilot hole through the hinge and board.

Flipping the board over, a 7/8" forstner bit was used to create a recess for the head of the carriage bolt. Next, the pilot hole was enlarged to 5/16", before the carriage bolt was fitted into it. I used a standard nut to tighten the carriage bolt into the wood as I was able to get it much tighter than I could with the wing nuts.

Step 17: Attach Handles

Two small holes were drilled in one end of both 1/2" box tubes to accommodate the 1" #10 screws. The box tubes were positioned on the bending angle just inboard of the hinges, and the holes in the tubes were continued through the angle. On the backside of the angle, the holes were countersunk to accommodate the heads of the screws (I used flat head screws). Once all the holes were drilled, the handles were bolted onto the bending angle.

Step 18: Bend Away

I primed and painted the brake to give in a nice finished look and was very happy with how it came out. Currently I don't have a permanent home for the brake, so I simply clamp the wood board to our kitchen table. This was the reason why I made the wood longer than the brake as I knew it would have to be used in this configuration for the time being.

I've only used it to bend a small piece of 1/16" aluminum (most likely similar to what I'll typically use it for), but it bent it like it was cheese. I'm confident it can handle a much wider piece of aluminum and even thin steel. The working area is around 17" wide, which should be more than wide enough for my current needs. I'm excited to finally be able to bend stuff correctly and know that this brake will get plenty of use in the future.

Be the First to Share


    • Furniture Contest

      Furniture Contest
    • Reuse Contest

      Reuse Contest
    • Made with Math Contest

      Made with Math Contest

    131 Discussions


    3 years ago

    Could you please provide a detailed cross section. Your opening picture would have helped except it does not show the entire end. Thx

    2 replies

    Reply 2 years ago

    I apologize for this taking so long, but here is a cross-sectional drawing of the side of the brake. Hopefully this helps :-)

    Side View of Brake Drawing.jpg

    17 hours ago

    Put a drop of oil on the hacksaw blade, and repeatedly put a drop of oil onto drill bits, when drilling metal, whenever you can see the shiny metal under the drill bit top. It will make things a lot easier for you and save you money on drill bits and hacksaw blades which wear too quickly.

    For bending cardboard, I run a blunt ... something (a spoon handle, a plastic spatula, a piece of left over thin plexiglas, whatever I have at hand) along a ruler, onto the surface of the cardboard, on the inside of the bend, a few times, also depending on the thickness of the cardboard. After that, it will bend perfectly along that line.


    2 years ago

    I was wondering if this could be extended to make a 6 foot brake. All the dimensions would remain the same, except the length of the bending surface would be extended. Thanks for the great instructable and any input.

    5 replies

    Reply 2 years ago

    You could. However, if you go any longer than I did I would recommend using thicker (and wider - longer legs) angle iron. The reason being that extra support will be needed to keep everything straight in the distance between the hinges. Great question!


    Reply 4 months ago

    ... or you could add a hinge or two.


    Reply 17 hours ago

    If you add a hinge in the middle, you break the width - can't stick wide stock into the brake anymore. Which defeats the purpose for making it wider.


    Reply 4 months ago

    Either wider sided angle iron or two or three pieces of angle iron of different width of the sides placed one into the other and screwed together. With three pieces screwed together with 1/4" screws every 2", placed at an offset of 1" on the sides, I think you'd get excellent rigidity. But it would be a lot of drilling and filing and screwing.


    Reply 2 years ago

    Thanks for the information. That is a good suggestion to use thicker angle iron. I have a project that requires a six foot brake, and this is a great alternative to paying several thousand dollars for a prebuilt one.


    4 months ago

    Wow so many safety concerns. A guy I know has only an index finger and thumb on his right hand. 3 fingers amputated from an infection gone bad, from guess what? Wiping away dirty, oily drill shavings! I'll bet you were not wearing eye protection either! And that knee vise - classic.. But hey your young right?! Plenty of time to heal. Except you cannot grow back fingers or eyes.
    Your next project should be a proper work bench. It'll make things so much easier AND safer.
    Giving all that criticism - its just because I hate to see you or anyone's effort and enthusiasm cut short by an unfortunate event. I'm a retired manufacturing engineer, and a died-in-the-wool DIYer - trust me they happen. And it's usually from something you know better than to do.

    2 replies

    Reply 3 months ago

    While your concerns are noted - not everyone can do things with "proper work benches". Ya work with what you have. I wouldn't have done that with a hacksaw either - but maybe it's all he's got. I've been doing wood working projects on a cardboard box sitting on 2 folding metal sawhorses, because my "proper work benches" are piled full of stuff. My work is better than anything you can buy as well. I'm gonna build this unit but make it to do up to 26" wide, and will weld the bend bar instead of the cap screws.


    Reply 17 hours ago

    If you build it wider, use angle iron with wider sides. Otherwise the brake itself will bend.


    4 months ago

    You need a foldable workbench and an angle grinder. The more so if you like to work with metal.

    Not that difficult to build either. Two collapsible sawhorses that can be locked into working position with screws, so they have good rigidity, with a working surface that also gets screwed in. When folded, you can store everything under the bed.


    4 months ago

    I'm impressed by your hacksawing technique! Despite having little to no support under the work, and holding the saw one-handed, you produce more accurate cuts than I can. And I have a bench vice and two hands on the saw!. Even in this age of powered disc grinders and such, I prefer to use a hacksaw, possibly because it costs nothing to run and makes much less noise. Also I need the practice.


    4 months ago

    I would have left more than 3/8 outside the hinge so you could do closed box folds. Just have to work out how big a box you'll make and it'll slip in from either side, admittedly you would have to use a vise or narrow table for full clearance for the bend. Professional ones have this as well as a set of bend plates (the bend plates are either 50mm (2 inch) or 75mm (3 inch).
    Great build and relatively easy thank you.


    Reply 4 months ago

    Not a necessary comment. Who cares if he is a DIY and makes it work and you are a DIY and you cannot make it work. Negativity is not working anywhere in this world.


    Reply 2 years ago

    It's hardly impractical if you need a metal brake.