Mega Square

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  • Mega Square
  • Mega Square
  • Mega Square
  • Mega Square
  • Mega Square
Frequently bought together:


The original Mega Square is available in a 12 or 8 inch size with two material choices: Cast Iron (FE) or Cast Aluminum (AL). All Mega Squares feature a stiff “flange and web” design that is fully machined on all outer edges with tapped holes on the sides for mounting tabs.

Made In USA - Patent Pending

Roomy joint access for welding, gluing, nailing, riveting, etc.

Whatever process you’re working with, it probably benefits from some clearance around the joint.

Tabs help eliminate twisting and warping in the final work-piece.

The machined squares and tabs always create the perfect plane for your work-pieces to rest on. Tabs also let you easily hold round tubing.

Clamping is simple with multiple surfaces for quick and rigid attachment.

Stop spending your time and focus figuring out clamping strategies, or worse, clamping your straight workpiece to crooked surfaces.

Perfect For Angle Iron

Designed to quickly set your work-piece to 90 or 45 degrees. Speed squares and machinist squares are made for visual inspection and checking AFTER setup, the Mega Square is designed to get those parts square in the first place.

Flange & Web

  • 12” squares have a profile similar to an I Beam where the web is centered on the flanges.
  • 8” squares are similar to a “C” channel where the web is off to one side of the flange.
Customer Reviews

"Awesome squares. I also ordered the extra tabs. I use them constantly as my worksuraces are all slightly bent. These squares fix that as it's the contact with the material and the squares that render the work surface defects moot! I will be buying more possibly the minions but definently the angle squares I really need those. I'm an artist so I get crazy angle request."

Alma L.
"I've been fabing a few years now, and just recently started to do bigger projects, and haven't made the investment into a proper fab table yet. And I can tell you this is must have if you don't have a fixture table. But the great thing about fireballs squares are that if you do a Fab table then these are great addition to it! You can start with these at a lower entrance fee and make more money with better quality and increased production speed, and then get your table and continue to use them with even greater versatility. I picked up a 12" aluminum Mega Square, and I'm already planning on getting the 12" Monster Square. And I personally went with the 12" over the 8" because the larger squares are able to work on smaller projects as well as the big ones."
Earl K.


Mega Square 12"

For tubing 2 inch and larger, we suggest 12” squares (3” wide)

Mega Square 8"

For tubing 2 inch and smaller, we suggest 8” squares (1.5” wide)

Size (in) Weight (lbs) Material Flange (in)

Mega 12" FE

12" x 12" x 3"


Cast Iron


Mega 12" AL

12" x 12" x 3"


Cast Aluminum


Mega 8" FE

8" x 8" x 1.5"


Cast Iron


Mega 8" AL

8" x 8" x 1.5"


Cast Aluminum


Aluminum vs Cast Iron

Cast Iron


  • Great for heavy duty projects
  • Excellent resistance to deformation and raising burrs when scratched.
  • Some natural resistance to weld spatter.


  • Heavy (Not ideal for mobile welding)
  • Susceptible to rust.



  • Lightweight (Ideal for welding on the go)
  • Resistance to deformation vs aluminum billet
  • Some natural resistance to weld spatter.


  • Can be be damaged if dropped or if used in heavy duty projects.

Included Accessories

4 Edge Location Tabs

Our revolutionary tabs allow you to align your material up so that you don’t even need a welding table! Don’t spend thousands on a flat table, just use our squares! Tighten the tabs onto the front or back of your square and you can immediately get to work. Sure, there are different jigs out there, but can they line your material perfectly in seconds?

4 Tool-less Thumbscrews

But it doesn’t stop there. We reinvented the game by introducing our thumbscrews. Say goodbye to your hex keys and Allen screwdrivers and freely adjust the tabs with only your fingers!

Optional Add-ons

Edge Alignment Pins

Install our edge alignment pins on any square to create a large, overhanging edge which can be used to index the square on a different plane. Depending on the square, this allows you to create edges which are 90 degrees (perpendicular), 45 degrees, parallel, and even 60 and 30 degrees from the edge.

  • Use it with our Monster squares to create a speed square for layout.
  • Use it to hang the square off the edge of a table for working vertical or perpendicular to table surface
  • Use it to elevate the squares off the ground or table for extra clearance when you’re fitting and welding entire frames
  • Tip! If trying to create a parallel edge with the mega square for marking, use our shims to get that perfect distance!

Optional Back Oxide Coating

What is Black Oxide?

Black Oxide, blackening, oxidizing, oxiding, black passivating, gun bluing . . . these terms all refer to the process of forming a black iron oxide on the surface of ferrous metals.

The black oxide process is a chemical conversion coating. This means that the black oxide is not deposited on the surface of the substrate like nickel or zinc electroplating. Instead, the black oxide coating is produced by a chemical reaction between the iron on the surface of the ferrous metal and the oxidizing salts present in the black oxide solution. These oxidizing salts include penetrates, catalysts, activators and proprietary additives which all take part in the chemical reaction. The result of this chemical reaction is the formation of black iron oxide, magnetite (Fe3O4), on the surface of the metal being coated. Black oxide has a range of unique properties and benefits including corrosion protection & reduced friction.

Our Other Squares

  • The original Monster Square is available in a 12 or 8 inch size with two material choices.
  • The Monster Square is designed to quickly set your work piece to 90 or 45 degrees.
  • Clamping is simple with multiple surfaces for quick and rigid attachment.
  • Use the radius on the tabs to use the Monster Square as a traditional speed square for layout.
  • Use it as an ordinary, adjustable angle square that adjusts from 40 to 180 degrees.
  • Right Angle 90 Degree Square with generous weld accessibility. Total height of 8” in this configuration.
  • Tall 12” square when fully opened and locked into place
  • Remove the fasteners to get two individual squares
  • Use the large V-groove to hold large round tubing or pipe
  • Compact configuration for use in tight spaces.
  • 6" x 4" x 1.5", the 4" width is perfect for picket spacing on gates and fences.
  • They are the first square we offer which has a built in 60/30 degree angle.
  • The cutout provides just the right amount of joint access when using it to clamp things at 90 degrees.  

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61 Reviews

  • 5
    Mega Square

    Posted by Patrick Kachmar on Aug 20th 2021

    These things are awesome! Theyre worth every penny by trust me... Buy the 12 inch square. Even if you have to wait.

  • 5
    Great Mega Square

    Posted by Carlos Quezada on Aug 16th 2021

    This Mega Square is a great tool. Clamping is simple and this product delivers.

  • 5
    Mega Square

    Posted by Andrew Johnston on Aug 5th 2021

    Looks like what I was expecting... cant wait to use!!

  • 4
    12 inch aluminum mega square

    Posted by Dennis on Jul 1st 2021

    Just wish they were cheeper to purchase..

  • 5
    Mega Square

    Posted by Logan Hampton Brown on Jun 29th 2021

    Super helpful, excellent design

  • 5
    Thumbs Up (All the thumbs)

    Posted by A Squared Services on Jun 18th 2021

    So glad to have finally picked up the 8 inch aluminum Mega Square, sad I hadnt done it sooner. This was perfect for aligning the rectangle tubing and much more.

  • 5
    Mega Square

    Posted by Duke’s Iron Works on Jun 9th 2021

    Well designed. Works very well for set up and true square for layout and weld applications.

  • 5
    Great tool, returned for a second!

    Posted by Kris on May 9th 2021

    This thing is so useful! I now have two..... cant recommend enough!

  • 5
    Mega Square

    Posted by Carlos Quezada on May 4th 2021

    This product is sturdy and extremely well made. I just received it not too long ago and have used it on a few projects already. Good job Fireball

  • 5
    Mega is the Name

    Posted by Michael Chrest on Apr 29th 2021

    Wow. When the package arrived I thought someone had screwed up and sent me the cast iron square by mistake. It is mega!!! Im glad I picked aluminum now I cant imagine using the cast iron version of this beast. The size is great for what Im doing, but you dont get the heft through the internet. Ten stars!

  • 5
    Mega Square

    Posted by Randy Peterson on Apr 25th 2021

    Great Product. I made the mistake of only buying 1

  • 5
    Meg Square

    Posted by Ricardo O Trevino on Apr 16th 2021

    The squares work very well I’m very impressed on how fast and easy it is to set up and makes my job very easy planning to buy more in the future.

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