Typical Metal Types for Fabrications

Stainless steel

is defined as a ferrous alloy with a minimum of 10.5% chromium content. The name originates from the fact that stainless steel does not stain, corrode or rust as easily as ordinary steel. This material is also called corrosion resistant.

Stainless steels have higher resistance to oxidation (rust) and corrosion in many natural and man made environments.

Stainless steel's resistance to corrosion and staining, low maintenance, relative inexpensive and familiar luster make it an ideal base material for a host of commercial applications.

Stainless steels will be more expensive than standard steel but does not require painting or treating after production.

Aluminum

is found primarily in bauxite ore and is remarkable for its resistance to corrosion (due to the phenomenon of passivation) and its light weight. The metal is used in many industries to manufacture a large variety of products.

Aluminum is a soft, lightweight metal with normally a dull silvery appearance caused by a thin layer of oxidation that forms quickly when the metal is exposed to air. Aluminum is nontoxic (as the metal), nonmagnetic, and nonsparking. Aluminum is about one-third as dense as steel or copper; it is malleable, ductile, and easily machined and cast. It has excellent corrosion resistance and durability because of the protective oxide layer.

Improper use of aluminum may result in problems, particularly in contrast to iron or steel, which appear "better behaved" to the intuitive designer, mechanic, or technician. The reduction by two thirds of the weight of an aluminum part compared to a similarly sized iron or steel part seems enormously attractive, but it must be noted that this replacement is accompanied by a reduction by two thirds in the stiffness of the part. Therefore, although direct replacement of an iron or steel part with a duplicate made from aluminum may still give acceptable strength to withstand peak loads, the increased flexibility will cause three times more deflection in the part.

Aluminum will be more expensive than standard steels and approximately the same cost as stainless steel.

Carbon Steel

is an alloy primarily composed of iron, with carbon content between .02% and 1.7%. depending on grade. Carbon is the most cost effective alloying element for iron. Commercial grades of steel used in the production of brackets and fabrications are typically supplied in sheets with thicknesses described as gauges. Typical gauges would be 12 (.10”), 14 (.075”), 16 (.060”), 20 (.035”)gauge. Plate steel would be described in thickness of 3/16 (7 ga), ¼” ,3/8” and ½”.

Light gauge sheet steel (12 gauge to 20 gauge) would normally be cold rolled and have a smooth, clean surface. Heavy gauge steels (3/16” to ½”) are typically hot rolled. The surface is rougher than cold rolled but still acceptable for most applications.

Steel is the most cost effective and durable material available for fabrications. It is not resistant to rust so therefore needs surface coverage. (See Typical Material Coatings for Resistance to Rust)

Typical Metal Coatings for Resistance to Rust

Galvanized Steel Sheet

Hot-Dip Galvanized Sheet is carbon steel sheet coated with zinc on two sides by the continuous hot-dip process. The process results in a layer of zinc on each side of the steel sheet that is tightly adhering to the steel through the formation of an iron-zinc alloy bonding layer that is formed by a diffusion process while the heated steel strip is in contact with the molten zinc.

The steel gets coated in layers of zinc because rust won’t attack this protective metal.

If galvanized steel is lasered or cut, the edges will not be protected from rust since the zinc coating is layered on the outside of the sheet.

Hot Dip or Mechanical Galvanized Plating

Galvanizing at its most basic level is dipping steel products into a molten zinc bath. A metallic reaction ensues and a thin coating of zinc is formed, evenly covering all areas of exposed base metal. This simple approach is still used today; called after-fabrication hot dip galvanizing, this process is also commonly referred to as batch or general galvanizing. Products, assemblies, and fabrications coated with zinc by this process are most widely used in exterior applications but are also used in interior designs.

This is done to reduce corrosion (specifically rusting) of the ferrous item; while it is accomplished by non-electrochemical means, it serves an electrochemical purpose.

Galvanized steel is suitable for outdoor use if part is completely coated.

Steel Finishes

Below is a chart that shows some examples of the finishes that can be expected on steel materials.

	Aluminum Standard Finish
	Standard Steel Finish
	Floor Plate
	Galvanized Steel
	Jitterbug Non-symmetrical Sanded Finish
	Brushed Stainless Steel Finish
	Stainless Steel Polished No. 3 Finish

SRP Speciality Metals

Short Run Pro is capable of producing parts from any number of different materials and products. Our standard metals are Steel, Stainless Steel and Aluminum, however, along with these metals Short Run Pro uses the following materials for the right application:

• Expanded metal
  
  Expanded Metal is actually a class of material that is rigid, non raveling and has been slit and expanded. In the process the expanded metal will lose 80% of its weight but still retain strength. Most people refer to expanded metal as a mesh. There are numerous applications but because of ventilation properties and visibility most application are for guarding of machinery and personnel. This material can be made form steel, galvanized, stainless or alloy steel.
  
  Short Run Pro carries, as a standard, flattened steel product of ½” #16 expanded. Flatten, expanded metal is a process where the metal is run through a mill to produce a flat and smooth surface. The ½” #16 flattened expanded is the industry standard for expanded metal and recommend in most any guarding application.
  
  If specialty material is needed, such as galvanized or smaller opening (1/4”), Short Run Pro can provide it upon request. Lead-time may be extended due to delivery.
  
  
• Diamond Plate, Tread Plate or Floor Plate
  
  All of the above are interchangeable names in the industry for a type of metal stock with a regular pattern of raised diamonds or lines. Diamond Plate usually refers to an aluminum product but Tread Plate and Floor Plate usually refers to a steel product.
  
  These products are typically used in stairs or catwalks in industrial areas. The added texture reduces risks of slipping and many times the tread plate is used to cover cutouts in floors where wiring may be passing. Diamond plate is also used in decorative applications such as garages or shops. Steel tread plate is usually thicker plate form 3/16” to ¾”.
  
  
• Perforated Material
  
  Again this is a classification of a broad range of materials that uses round, square, slotted or decorative perforations. This product is used primarily as screens, diffusers, guards, filters, and vents.
  
  Short Run Pro stocks a 14 ga 3/16-1/4 stagger steel perforated material. This is a general purpose material suitable for most applications. (3/16 describes the hole size and the ¼” describe the stagger from one row of holes to the next). There are numerous perforated configurations that are available.
  
  
• Lexan
  
  Lexan is commonly described as an acrylic but has properties that make it far more durable. Lexan can be a clear or colored plastic that can be lasered, drilled and punched unlike a Plexiglas and can even be formed.
  
  Short Run Pro has numerous sizes of Lexan available for applications such as covers.