Welding & Joining Technology: Fabricating

Fabrication Series 

Fabrication Series created by Tim McAmis Performance Parts

Edison Welding Institute (EWI) 

MIG Welding - the DIY Guide 

Guide to welding and fabricating

The Fabricator 

Everything there needs to know about fabricating and welding

Welding Fabrication 

The process of assembling the parts to form a weldment. It can include layout, measuring, cutting, grinding, fitting, tack welding, etc.

Weldment is a general term that refers to anything that was created primarily by welding. It may form a completed project or may only be part of a larger structure.

Custom fabrication: all or most of the assembly is handmade.

Metal fabrication is the creation of metal structures by cutting, bending and assembling processes.

Fitting is the process of adjusting the parts of a weldment so that they meet the overall tolerance because not all parts fit exactly as they were designed. There may be slight imperfections in cutting or distortion of parts due to welding, heating, or mechanical damage. 

Fixtures are devices that are made to aid in assemblies and fabrication of weldments.

Tack welds are welds (usually small in size) that are made during the assembly to hold all of the parts of a weldment together so the welding can be finished

Kerf is the space created as material is removed during a cut

Tolerance is the amount that a part can be bigger or smaller than it should be and still be acceptable.

Assembling is done by welding, binding with adhesives, riveting, threaded fasteners, or further bending in the form of crimped seams. Structural steel and sheet metal are the usual materials for fabrication; welding wire, flux and/or fasteners are used to join the cut pieces.

• Cutting.  sheets of metal are split into halves, thirds or smaller sections. Can be freshley cut or pre-shaped metals like bars and measured panels that need to be cut. Cuts are performed on a range of machinery, from lasers and plasma torches to more elaborate, high-tech pieces of machinery.

• Folding. One of the more complicated processes of metal fabrication involves folding, where a metal surface is manipulated to shape at a certain angle. 

• Welding. Along with cutting, welding is one of the most popular metal fabrication processes among crafts enthusiasts. The process of welding involves the joining of two separate metal parts. 

It’s important to consider these factors when deciding on the type of welding technique to use for metal fabrication:

• The type of metal
• The thickness of the metal
• The size of the welding project
• What you want the welds to look like
• Your overall budget
• Whether you’re welding indoors or outdoors

• Machining. When a machine is used to remove portions from a piece of metal, the process is known as machining. Typically, the process is performed on a lathe, which will rotate the metal against tools that trim corners and edges to cut the piece down to a desired shape or measurement. 

• Punching. When holes are formed in a piece of metal, the process involved consists of punching, where metal is placed under a die and submitted to a punch-through by a drill. For the punch to be the correct size, the circumference of the drill must slot correctly through the die. 

• Shearing. For sheets of metal that require long cuts, the process is known as shearing. In some cases, the sheet is fed horizontally through a metal-cutting machine. In other applications, a cutting tool is applied vertically against the length of a flat metal sheet. A third method involves placing the metal over the edge of an open cutter and lowering the blade, much like the paper cutters found at copy facilities. Shearing is often applied to trim down the edge of a metal sheet, but the process may be done anywhere along the metal.

• Stamping.  the process of stamping or creating an indentation is used to form certain shapes, letters or images within a metal sheet or panel. In effect, metal stamping is similar to relief carving in wood or marble. A primary example of metal stamping is seen on coins, where words, currency amounts and the faces of presidents are stamped from each surface side on pennies, nickels, dimes and quarters.

• Casting. One of the oldest types of metal fabrication involves casting, where molten metal is poured into a mold and is left to solidify into a specific form. The most common metals employed in this application include steel, iron, gold, copper, silver, and magnesium.