Challenger Sheet Metal, Inc. is your Southern California sheet metal fabrication shop that currently stocks these metal products below. Please be sure to contact us with any questions you might have!

• Galvanized G90 steel, 26 thru 10 gauge 4’0” x 10’0” sheets
• Galvanized & Galvalume 26, 24 & 22 gauge coil stock
• Pre-finished (limited colors) 24 gauge 4’0” x 10’0” sheets
• Pre-finished (limited colors) 24 gauge coil stock
• Some aluminum and stainless steel 4’0” x 10’0” sheets
• 16 & 20 ounce Copper coil and flat sheet stock

Shearing is a metal fabricating process used to cut straight lines on flat metal stock. During the shearing process, an upper blade and a lower blade are forced past each other with the space between them determined by a required offset. Normally, one of the blades remains stationary.

Characteristics of the shearing process include:

• Its ability to make straight-line cuts on flat sheet stock
• Metal placement between an upper and lower shear blades
• Its trademark production of burred and slightly deformed metal edges
• Its ability to cut relatively small lengths of material at any time since the shearing blades can be mounted at an angle to reduce the necessary shearing force required.

Limitations –

The use of shears in sheet metal production has diminished through the use of cut-off tooling in CNC punching and the use of shake-out technology to separate parts from the sheet skeleton. Shears are used mainly for rough shearing sub-sizes of sheets for CNC presses or strips for stamping press dies.

In those cases where finished dimensions are sheared, the thickness of the material and the X-Y dimension of the part dictate the degree of precision which is feasible economically. Thicker material and greater X-Y dimensions require greater tolerances.

Process –

Typically, the upper shear blade is mounted at an angle to the lower blade that is normally mounted horizontally. The shearing process performs only fundamental straight-line cutting but any geometrical shape with a straight line cut can usually be produced on a shear.

Metal shearing can be performed on sheet, strip, bar, plate, and even angle stock. Bar and angle materials can only be cut to length. However, many shapes can be produced by shearing sheet and plate.

Materials that are commonly sheared include:

• Aluminum
• Brass
• Bronze
• Mild steel
• Stainless steel

Challenger Sheet Metal, Inc. – Capabilities

• Bending and forming up to 26 foot long in 26, 24 & 22 gauge, from coil stock only.
• Shearing & cutting (thru our coil “Slasher”) in 26, 24 & 22 gauge, from coil stock only.
• Bending and forming up to 10 foot long in 26 thru 14 gauge (12 & 10 gauge in mild steel only).
• Shearing and cutting up to 10 foot long in 26 thru 14 gauge (12 & 10 gauge in mild steel only).

Brake forming is one of the oldest mechanical metal deformation process. During the process, a piece of sheet metal is formed along a straight axis. This may be accomplished by a “V”- shaped, “U”-shaped, or channel-shaped punch and die set.

Although press braking appears a simple concept, maintaining accuracy can often be quite difficult. Precision bending is a function of both the press, the tooling, and the work-piece material. Material properties such as yield strength, ductility, hardness, and the condition of the material, all affect the amount of spring back of the material.

The most common industrial press braking process is called air bending. Air bending relies upon three point bending. The angle of the bend is dictated by how far the punch tip penetrates the “V” cavity. The greater the penetration of the punch tip the greater the angle achieved.

The main benefit of air bending is that it uses much less force than other methods to achieve a 90° bend due to the leverage effect.

Characteristic of the metal brake forming process include:

• Its ability to form ductile materials
• Its use in both low and medium production run applications,
• The need for minimal tooling,
• Its suitability to produce smaller parts,
• Its output of long workpieces using a “V”, “U”, channel, or other special punch and dies.

Brake forming can commonly form metals up to 10″ thick and some machinery will form pieces as long as 20 feet. Materials commonly used in the brake forming process include:

• Aluminum
• Brass
• Cold rolled carbon steel
• Hot rolled carbon steel
• Stainless steel

Tool materials for brake forming —

1. Low-carbon steel is used for low production runs, die and punch base material, and soft to medium hardness materials.
2. Tool steel is used for medium to high production, for medium to server bending, and for medium to strong materials.
3. Carbide tools are used for high production runs on materials that required severe bending, and are usually designed as tool inserts.
4. Hardwood tools are used for very low production runs, for very simple bending applications, and are normally used on very soft materials.