Using a vast number of specialized tools and metal fabricators at our disposal, ChinaSavvy has become a leading metal fabrication company delivering high quality precision metal fabrications at competitive China prices.

• Metal Forming
• Shearing
• Material Removal
  • Including boring, drilling, grinding, milling, sawing, tapping and turning.
• Advanced fabrication methods that include laser cutting, plasma cutting, water jet cutting and Wire Electric Discharge Machining (EDM).
• Welding and Assembly
  • Including Tungsten Inert Gas (TIG) welding, Metal Inert Gas (MIG) welding, Robot welding and Friction Stir Welding (FWS).

Sheet Metal Fabrication

One of the most common forms of raw material stock, sheet metal fabrication entails the shaping of a piece of sheet metal (being the workpiece) into the desired part. Note that sheet metal is considered to be a piece of stock between 0.006 inches (0.152 mm) and 0.25 inches (6.35 mm) thick.

A piece of metal that is thicker is referred to as plate, while thinner metal is referred to as foil.

At ChinaSavvy, the sheet metal stock available range to include aluminum, brass, bronze, copper, magnesium, nickel, stainless steel, steel, tin, titanium and zinc.

Sheet metal fabrication processes can be divided into:

• Forming
• Cutting

 

Forming

Forming processes are capable of bending and stretching sheet material into the desired shape without causing the material to fail. Entailing the application force that causes the material to plastically deform, forming processes include:

Bending

Here, a force is applied to a piece of stock (sheet metal) causing it bend at an angle, effectively achieving the desired shape. Bending processes result in deformation along one axis, but with a sequence of processes, more complex parts can be formed.

Note that bending operations do result in compression and tension. The outside of the sheet metal being bent will undergo tension as it stretches to a greater length. The inside section of the portion that experiences the stretch, will now experience compression.

Another important factor to consider regarding bending is springback. Due to elastic recovery, sheet material needs to be over-bend to an exact measurements in order to achieve the exact bend angle and bend radius required.

Typical machines used for bending processes include press brakes, but custom tooling can also be used to create specialized bending processes. Other processes used for bending also includes V-Bending and Wipe Bending.

Deep Drawing

This sheet metal fabrication process entails the sheet metal to be stretched into a desired shape by using a tool, pushing downwards, to push the sheet material into a die cavity (which is in the shape of the required part).

An effective process for ductile metals such as mild steel and aluminum, deep drawing creates a number of everyday products ranging from pots and pans, to fuel tanks and automotive bodies.

Roll Forming

Entailing sheet metal to be progressively shaped through a series of bending operations, the roll forming process involves a roll forming line in which sheet stock is fed through a series of roll stations, each station featuring a roller die, positioned on both sides of the sheet being formed.

Note that these roller dies, lubricated in order to reduce the friction created between the sheet metal and the die, can be positioned below, above, at an angle or along the sides of the sheet metal being formed.

The roller dies used can be unique to every station, or identical roller dies can be used in different positions.

Spinning

Used to form cylindrical parts, spinning entails the rotation of sheet metal stock while a force is applied to this stock at one side. Typically performed on a CNC or manual lathe, spinning requires a roller tool, blank and mandrel.

The blank is the disc-shape sheet metal (pre-cut) with the mandrel being the solid form of the internal shape to be formed. The blank is pressed against the mandrel and, for more complex parts, multi-piece mandrels can be used.

The roller wheel is responsible for applying force as the blank and mandrel rotate, resulting in the sheet being bent around the mandrel.

Two spinning methods are used, which includes:

• Conventional Spinning
  • Here, the roller tool is pressed against the blank until it conforms to the shape of the mandrel. The now spun part will have a smaller diameter than the blank and have a constant thickness.
• Shear Spinning
  • In shear spinning, the roller tool is not only responsible for bending the blank against the mandrel, but is also applies a downward force as it moves. This causes the sheet metal to stretch over the mandrel. With this spinning process, spun parts will remain equal to the original blank diameters with the wall thicknesses of the parts being thinner.

 

Stretch Forming

This forming process entails a piece of stock (sheet metal) being bent and stretched over a form die, resulting in the formation of large, contoured parts. Bending and stretching occurs simultaneously and this process is commonly used to form large radius bends.

Stretch forming is capable of producing simple curved surfaces as well as complex, non-uniform cross sections, with the most common materials shaped including steel, aluminum and titanium.

Parts formed using this process range from wing panels on airplanes and door panels on cars, to enclosures and window frames.

Cutting

Cutting processes within sheet metal fabrication causes the stock to fail or separate – this allows for sheet material to be cut or removed.

Cutting processes can be further divided into:

• Cutting with Shear
• Cutting without Shear

 

Cutting with Shear

Within fabrication, most cutting processes are achieved by applying a shearing force to the sheet metal material, allowing for a cut to be made.

Shearing force is applied by two tools – one from above and one from below – reaching the material’s ultimate shear strength, which causes the material to fail and cut to be made.

Processes that applies shearing force includes:

• Shearing
  • This process entails straight line cuts to separate a piece of sheet metal and is most commonly used to cut sheet stock into smaller sizes for use in other sheet metal fabrication processes.
• Blanking
  • Used to cut blanks for use in other processes, blanking is capable of cutting out parts in various two-dimensional shapes.
    • Conventional Blanking – Using a blanking press, sheet metal stock, blanking punch and blanking die, this method involves the stock to be over the die, which has a cutout of the desired shape, in the blanking press. A hydraulic press now, at a high speed, pushes the blanking punch downwards causing the metal to bend and fracture.
    • Fine Blanking – A more specialized method, this process entails the use of three separate forces. A downward holding force (applied to the top of the sheet), a cushion that provides a counterforce (underneath the sheet directly under the punch) and the blanking punch (which impacts the sheet). This method is capable of creating tight tolerances, better flatness and smoother edges with minimal burrs.
• Punching
  • Here, the material being removed from the sheet metal is the scrap (also referred to as the slug), laving behind the desired feature in the sheet. Typically punching involves the use of cylindrical punch tool responsible for piercing the sheet and forming a single hole. Punching can be done by manual press punches or by using CNC punch presses, which can be pneumatically, hydraulically or electrically powered.
  • Do not however that punching is capable of creating a number of different features using various operations. Some of these punching operations include cutoff, dinking, slitting, piercing, trimming, nibbling, slotting, shaving, lancing, perforating and notching, to name but a few examples.

 

Cutting without Shear

Cutting processes in this category do not use shear force, but instead applies forces such as abrasion or thermal energy to form a cut. Some of the common cutting processes here range to include:

• Laser Cutting
• Water Jet Cutting
• Plasma Cutting

 

Based in Guangzhou, China, ChinaSavvy is your reliable precision metal fabrication company specializing in sheet metal fabrication that range to include Stainless Steel fabrication and Aluminum fabrication.