A Guide to Metal Fabrication

What does bespoke metal fabrication involve? What is CNC laser cutting? How does MIG welding differ from TIG welding? Sharing ASA Fabrications’ years of knowledge and experience in the industry, this guide will answer all those questions and more…

What is metal fabrication?

Metal fabrication is the forming of metal parts and products using methods such as cutting, punching, bending, welding, assembly and finishing. While humans have been mining and machining metal for centuries, the techniques and equipment used in these processes have evolved, incorporating computer technology to increase efficiency and quality, and reduce waste.

Which industries use metal fabrication?

Thanks to its flexibility and range of applications, demand for metal fabrication continues to grow. Here is a list of industries that rely on metal fabrication and the products/structures/applications involved:

• Automotive – vehicle frames, doors, engines, internal and external components, electronics
• Transport – vehicles (as above), seating
• Infrastructure – bridges, walkways, traffic lights, signage, art installations
• Aerospace – wings and fuselages
• Mining and construction – external building material, frames, beams, machinery, tools, bolts, screws, nuts, springs and wires
• Agriculture – machinery
• Medical – surgical equipment, tables, medical devices, cameras
• Energy – platforms, pipelines, equipment, turbines
• Electronics – contacts, enclosures, appliances

What are the different metal fabrication processes?

Designing and programming

Whether you have a detailed design specification, a part you want to replicate or just an idea, expert fabricators will work with customers to produce a design and programme that optimises the manufacturing process, producing precise designs and creating a 3D model for approval.

In the programming process, final designs are translated into shapes and patterns for the machines to cut, utilising as much material as possible to reduce waste and cost.

Cutting

There are many different types of cutting techniques available, depending on the choice of material, budget, order size, turnaround time, in-house expertise and more:

• Laser cutting: CNC laser cutting, whether for metal plates or tubing, is one of the most versatile and precise cutting methods available. A laser aimed at a surface creates enough heat that the material either melts or evaporates, creating a clean cut that accurately reflects the design and avoids additional finishing processes.
• Water jet cutting: Essentially an accelerated erosion process, water jet cutting fires highly-pressurised water (sometimes containing abrasive additives) at the surface to be cut.
• Plasma cutting: Plasma cutting works by forcing a heated, electrically-charged gas through a small nozzle to hit the workpiece at high velocity and pressure, eroding and melting a cutting path through the material.
• Flame cutting: As its name suggests, flame cutting uses a neutral flame and added oxygen stream to cut material.
• Manual cutting: Despite advances in technology, manual cutting techniques still have their place in the industry. They can include sawing and shearing.

We employ the Amada Ensis 3015 RI fibre laser, which easily switches between cutting flat sheet to tube or pipe cutting in only a couple of minutes.

Folding, bending or forming

Varyingly referred to as folding, bending or forming, the next fabrication stage involves folding cut parts in various ways to achieve a desired shape. As with cutting, the method chosen will depend on variables such as material, size/thickness, quantity and complexity. While small jobs may be folded manually, many are now carried out using a CNC press brake. With greater automation, metal fabricators use this technology to produce components like brackets, channels, enclosures, ductwork, and other custom and complex shapes.

At ASA Fabrications, our Amada HFEi 50 ton and Amada HFE 100 ton CNC press brakes form parts by clamping the sheet metal between a top tool and die, applying pressure to obtain the intended bend/shape. We stock an extensive range of tools and dies, and can order new ones for specific projects.

Machining

For the fabrication of metal parts, machining involves the removal of material and can mean drilling, tapping, milling or turning:

• Drilling uses a rotating drill bit positioned perpendicular to the workpiece to cut a round hole.
• Similar to drilling, tapping produces a thread in the side of the hole to match and accommodate almost any screw type available.
• Milling combines rotary cutting similar to drilling, but does so at the same time as the workpiece is moved horizontally, to create more complex shapes.
• In turning, it is the workpiece that is rotated, with a lathe machine moving the cutting tool in a linear fashion along the surface of the rotating workpiece.

Welding

Welding involves joining separate pieces of metal by applying high heat to melt one or both pieces before allowing them to cool and fuse together.

• MIG (metal inert gas) welding is an arc welding process in which a continuous solid wire electrode is fed through a welding gun and into the weld pool, joining two metal pieces together. A shielding gas is also sent through the welding gun and protects the weld pool from contamination.
• In contrast to MIG welding, TIG (tungsten inert gas) welding uses a non-consumable tungsten electrode that delivers the current to the welding arc. An inert gas, typically argon, protects and cools the tungsten and weld pool.
• Plasma arc welding is a precision technique very similar to TIG welding, but the electrode is recessed and the ionizing gases inside the arc are used to create heat.
• Electron beam and laser welding focuses beams and lasers at small weld points for high-accuracy, delicate jobs.

We specialise in manual MIG and TIG welding at ASA Fabrications and can help you decide which technique is the best for your project.

Finishing

Metal finishing is exactly what it sounds like – a final stage (or stages) in the metal fabrication processes that finishes off a piece. Metal finishes can involve cleaning or polishing the existing surface, or adding a substrate to the metal surface using powder coating, plating, lacquering or printing. Finishes can enhance either the aesthetic or performance.

Expert metal fabrication in Stoke-on-Trent

If you would like to find out more about the metal fabrication services offered by ASA Fabrications Ltd, please browse our website or get in touch.