Essential Techniques and Methods in Metal Processes

Manufacturing methods constantly evolve, with new technologies enabling better and faster ways of fabricating parts, from high-precision machinery to CNC and robotics.

However, not all of these are readily available without a large expenditure, and not all techniques can be applied to all metals. In this guide, we’ll take a look at some of the more common fabrication techniques.

Types of Metal Processes and Manufacturing Techniques

Fabrication techniques in general can fall into one of many categories, some pertaining to fabrication exclusively, and some branching out into related fields, such as machining. These include:

Joining

In order to create something from raw material, we need a way to attach two or more pieces. There are many methods fabricators use, depending on the size, type of material, and efficiency required. These include:

• MIG, TIG, MMA Welding
• Brazing
• Riveting
• Bolting

Welding is one area where there have been numerous advancements in the last few decades, from pulse and synergic welding to robotic and autonomous, robotic welding.

Cutting

Before joining any parts, they will need to be cut to the correct size and shape. All of the below operations are commonly now carried out by computer-controlled machines, defining the sizes and shapes in a program rather than by hand, but the older techniques are still just as useful:

• Sawing
• Laser, Plasma, Waterjet, Oxy-propane
• Shearing
• Punching

Forming

In many cases, the material, cut to the right size, in its natural shape, i.e., flat or straight, is not the most efficient process of manufacture; that is where forming comes in. These processes take a piece of material and change its shape, either for further processing or to complete a part:

• Bending
• Stamping
• Forging
• Rolling

Machining

Whilst not strictly under the same remit as fabrication, machining is a process linked tightly to fabrication, as both a primary and secondary process in the manufacture of all sorts of components.

These are some of the typical machining processes allied with fabrication:

• Drilling
• Turning
• Milling
• Surface Grinding

Key Techniques for Precision Metal Machining

Precision has always been the main benefit of machining as a manufacturing process; it enables precise tolerances to be achieved in round or square parts. The advent of CNC technology, however, added the ability to make any shape part, with multiple axes of rotation at once.

Many modern CNC machines can achieve an accuracy of +/-0.025mm without special considerations, and even higher tolerances if needed.

Advancements in Metal Fabrication Techniques

Like every manufacturing process, metal fabrication has seen its fair share of high-tech advancements in recent years. Some serve only to aid the fabricator, while others replace almost completely.

Robotics has been used in manufacturing for decades now, welding was one of the first processes to be used in conjunction with high-precision robotic arms, in factories making cars and other high-volume products.

Another revolutionary technique is additive manufacturing, which is the creation of a part by building up successive layers, either via a material melted through an arc process or sintered powder. This is in direct contrast to subtractive techniques such as machining.

Additive manufacturing is breaking boundaries of what is possible to be made from metal, with complex shapes unachievable through traditional methods.

Quality Control in Fabrication

Quality control, alongside an effective feedback system, is important in any manufacturing process; it is the cornerstone to reducing waste and retaining quality. There are a number of techniques utilized in metal fabrication.

• Process control: to ensure quality throughout the manufacturing process, each step should be tightly controlled, with outputs measured and logged
• Dimensional accuracy: Rarely do materials not undergo multiple steps before completion, be that cutting, forming or welding, each step can affect the accuracy of the next, and subsequently of the final part
• Welding control: Various testing and certification standards have been developed to enable effective welding processes to be used across thousands of parts and operatives, with the guarantee of weld strength and longevity