Rolled Steel Shapes

What Hot Rolled Steel Shapes are Available?

The typical shapes and their sizes and attributes are shown in the respective tables below:

W section steel property table	M section steel property table	S section steel property table
HP section steel property table	C section steel property table	MC section steel property table
L section steel property table	WT section steel property table	MT section steel property table
ST section steel property table	HSS (round) section steel table	HSS (rect) section steel table
Pipe section steel property table	2L section steel property table

What Sheet Metal Gauges are Available?

Sheet metal gets used in many applications, from forms for concrete pours on structural steel to flashings. The table below illustrates the available gauges for steel, galvanized steel and aluminum sheet metals:

Why are Connections so Important in Structural Steel?

Most structural steel failures happen at connections....where a beam connects to a column, where a joist connects to a beam, where a hanging rod connects to a beam (the Kansas City Hyatt discussed above). The Structural Engineer must design the design the steel members and give guidelines for the connections. Many people in the Construction Industry don't understand, though, that the Structural Engineer rarely designs the connections.

Why is that? Historically, the Steel Fabricators developed many different ways to make connections. What one Fabricator did in his shop economically might have been quite an expensive way to do it in a competitor's Fabrication Shop. So the practice developed that the Structural Engineer would size the members, but the Steel Fabricators would design the connections, which the Structural Engineer should then review and approve. If you think that seems like a complicated system prone to error, you'd be correct.

But that is the system we generally have in American construction. So the Construction Supervisor should know something about steel connections and have an idea if they are being installed correctly. A bit of background in Basic Structural Design is helpful, but the main thing to understand is the concept of pin connections versus fixed connections.

A beam bolted to a column with clip angles along the beam web likely creates a pin connection. This means that the beam shouldn't be able to move up or down, nor in or out, but it can rotate a bit. A steel column bolted to a concrete pier with four anchor bolts also typically creates a pin connection. Again the steel column won't go up, down or sideways, but it may be able to rotate a bit.

The fixed connection must stop that ability to rotate. So for a beam to have a fixed connection to a column, along with clip angles, there may be a plate on the top and bottom flanges of the beam that gets welded to the column. With all that welding, the beam can no longer rotate. If a steel column is buried four feet deep in a concrete pier, it also would not be rotating at the point that it exits from the concrete. So those are a couple of ways to create fixed (or moment resisting) connections.

The Construction Supervisor should be aware if any fixed (or moment resisting) connections are required and understand how they are to be made. Just asking the questions increases the likelihood of a successful project.

What is Composite Design?

Composite design marries some of steel and concrete's best attributes together for an efficient structural system. Let's start by thinking about a structural system that isn't composite design. Structural steel beams placed at 4' on center with a steel deck spanning perpendicular which will have 4" of concrete placed on top of the steel deck is not a composite system. That means the steel beams will carry their own weight, the weight of the steel deck and concrete above and whatever live load gets applied. The steel deck and the concrete must carry their own weight and the live load spanning from steel beam to steel beam. Another way to state the proposition: the steel beam acts on its own structurally and the steel deck and concrete act on their own structurally.

A composite system ties together that steel beam and concrete floor and forces them to act as a single structural unit. Some connector on top of the steel beam makes the steel and concrete act as one unit. The steel beam can't slide independently of the concrete slab, the two are bonded together. Since the concrete is strong in compression, the composite system can be quite efficient structurally. The figure below illustrates the concept.

What Public Domain Documents are Available for Further Study?

A two part Steelworker training course from the US Navy provides a tremendous amount of practical learning. TitledSteelworker Volume #1 at 247 pages and officially named NAVEDTRA 14250. And Steelworker Volume #2 at 417 pages and officially named NAVEDTRA 14251.

The Welding - Design, Procedures and Inspections Handbook produced by the US Dept of Defense provides many details describing water and sitework. The name of this document is UFC 3-320-01A 1 March 2005.

The US Dept of Defense Cold-Formed Load Bearing Steel Systems and Masonry Veneer/Steel Stud Walls is a design handbook that has information regarding steel systems and steel stud walls. The official name of this 148 page handbook is UFC 3-310-07A, 19 June 2006.

Tricks of the Trade & Rules of Thumb for Structural Steel:

1. Learn the names of the basic structural steel hot rolled shapes (W, HP, S, C, etc).
2. W, S, and M structural steel shapes tell their height and weight in their name (a W8 x 31 is 8" high and weighs 31 pounds per foot).
3. Always check if there are fixed (moment resisting) steel connections on the project.
4. Always check if a slab above steel beams acts as a composite system.
   

Carbon steel.

Carbon steel, also called plain-carbon steel, is steel where the main interstitialalloying constituent is carbon. The American Iron and Steel Institute (AISI) defines carbon steel as: "Steel is considered to be carbon steel when no minimum content is specified or required for chromium, cobalt, molybdenum, nickel, niobium, titanium,tungsten, vanadium or zirconium, or any other element to be added to obtain a desired alloying effect; when the specified minimum for copper does not exceed 0.40 percent; or when the maximum content specified for any of the following elements does not exceed the percentages noted: manganese 1.65, silicon 0.60, copper 0.60."^[1]

The term "carbon steel" may also be used in reference to steel which is not stainless steel; in this use carbon steel may include alloy steels.

As the carbon content rises, steel has the ability to become harder and stronger throughheat treating, but this also makes it less ductile. Regardless of the heat treatment, a higher carbon content reduces weldability. In carbon steels, the higher carbon content lowers the melting point.^{[2]Carbon steel, also called plain-carbon steel, is steel where the main interstitialalloying constituent is carbon. The American Iron and Steel Institute (AISI) defines carbon steel as: "Steel is considered to be carbon steel when no minimum content is specified or required for chromium, cobalt, molybdenum, nickel, niobium, titanium,tungsten, vanadium or zirconium, or any other element to be added to obtain a desired alloying effect; when the specified minimum for copper does not exceed 0.40 percent; or when the maximum content specified for any of the following elements does not exceed the percentages noted: manganese 1.65, silicon 0.60, copper 0.60."[1]}

The term "carbon steel" may also be used in reference to steel which is not stainless steel; in this use carbon steel may include alloy steels.

As the carbon content rises, steel has the ability to become harder and stronger throughheat treating, but this also makes it less ductile. Regardless of the heat treatment, a higher carbon content reduces weldability. In carbon steels, the higher carbon content lowers the melting point.^[2]

[edit]Types

See also: SAE steel grades

Carbon steel is broken down in to four classes based on carbon content:

[edit]Mild and low carbon steel

Mild steel is the most common form of steel because its price is relatively low while it provides material properties that are acceptable for many applications. Low carbon steel contains approximately 0.05–0.15% carbon^[1] and mild steel contains 0.16–0.29%^[1] carbon; therefore, it is neither brittle nor ductile. Mild steel has a relatively low tensile strength, but it is cheap and malleable; surface hardness can be increased through carburizing.^[3]

It is often used when large quantities of steel are needed, for example as structural steel. The density of mild steel is approximately 7.85 g/cm³ (7850 kg/m³ or 0.284 lb/in³)^[4] and the Young's modulus is 210,000 MPa (30,000,000 psi).^[5]

Low carbon steels suffer from yield-point runout where the material has two yield points. The first yield point (or upper yield point) is higher than the second and the yield drops dramatically after the upper yield point. If a low carbon steel is only stressed to some point between the upper and lower yield point then the surface may develop Lüder bands.^[6]

[edit]Higher carbon steels

Carbon steels which can successfully undergo heat-treatment have a carbon content in the range of 0.30–1.70% by weight. Trace impurities of various other elements can have a significant effect on the quality of the resulting steel. Trace amounts of sulfur in particular make the steel red-short. Low alloy carbon steel, such as A36 grade, contains about 0.05% sulfur and melts around 1426–1538 °C (2599–2800 °F).^[7] Manganese is often added to improve the hardenability of low carbon steels. These additions turn the material into alow alloy steel by some definitions, but AISI's definition of carbon steel allows up to 1.65% manganese by weight.

Medium carbon steel

Approximately 0.30–0.59% carbon content.^[1] Balances ductility and strength and has good wear resistance; used for large parts, forging and automotive components.^[8]

High carbon steel

Approximately 0.6–0.99% carbon content.^[1] Very strong, used for springs and high-strength wires.^[9]

Ultra-high carbon steel

Approximately 1.0–2.0% carbon content.^[1] Steels that can be tempered to great hardness. Used for special purposes like (non-industrial-purpose) knives, axles or punches. Most steels with more than 1.2% carbon content are made using powder metallurgy. Note that steel with a carbon content above 2.0% is considered cast iron.

[edit]Heat treatment

Iron-carbon phase diagram, showing the temperature and carbon ranges for certain types of heat treatments.

Main article: Heat treatment

The purpose of heat treating carbon steel is to change the mechanical properties of steel, usually ductility, hardness, yield strength, or impact resistance. Note that the electrical and thermal conductivity are slightly altered. As with most strengthening techniques for steel,Young's modulus is unaffected. Steel has a higher solid solubility for carbon in the austenitephase; therefore all heat treatments, except spheroidizing and process annealing, start by heating to an austenitic phase. The rate at which the steel is cooled through the eutectoidreaction affects the rate at which carbon diffuses out of austenite. Generally speaking, cooling swiftly will give a finer pearlite (until the martensite critical temperature is reached) and cooling slowly will give a coarser pearlite. Cooling a hypoeutectoid (less than 0.77 wt% C) steel results in a pearlitic structure with α-ferrite at the grain boundaries. If it is hypereutectoid (more than 0.77 wt% C) steel then the structure is full pearlite with small grains of cementite scattered throughout. The relative amounts of constituents are found using the lever rule. Here is a list of the types of heat treatments possible:

• Spheroidizing: Spheroidite forms when carbon steel is heated to approximately 700 °C for over 30 hours. Spheroidite can form at lower temperatures but the time needed drastically increases, as this is a diffusion-controlled process. The result is a structure of rods or spheres of cementite within primary structure (ferrite or pearlite, depending on which side of the eutectoid you are on). The purpose is to soften higher carbon steels and allow more formability. This is the softest and most ductile form of steel. The image to the right shows where spheroidizing usually occurs.^[10]
• Full annealing: Carbon steel is heated to approximately 40 °C above Ac₃ or Ac₁ for 1 hour; this assures all the ferrite transforms into austenite (although cementite might still exist if the carbon content is greater than the eutectoid). The steel must then be cooled slowly, in the realm of 38°C (68.4°F) per hour. Usually it is just furnace cooled, where the furnace is turned off with the steel still inside. This results in a coarse pearlitic structure, which means the "bands" of pearlite are thick. Fully-annealed steel is soft andductile, with no internal stresses, which is often necessary for cost-effective forming. Only spheroidized steel is softer and more ductile.^[11]
• Process annealing: A process used to relieve stress in a cold-worked carbon steel with less than 0.3 wt% C. The steel is usually heated up to 550–650 °C for 1 hour, but sometimes temperatures as high as 700 °C. The image rightward shows the area where process annealing occurs.
• Isothermal annealing: It is a process in which hypoeutectoid steel is heated above the upper critical temperature and this temperature is maintained for a time and then the temperature is brought down below lower critical temperature and is again maintained. Then finally it is cooled at room temperature. This method rids any temperature gradient.
• Normalizing: Carbon steel is heated to approximately 55 °C above Ac₃ or Ac_m for 1 hour; this assures the steel completely transforms to austenite. The steel is then air-cooled, which is a cooling rate of approximately 38 °C (68 °F) per minute. This results in a fine pearlitic structure, and a more-uniform structure. Normalized steel has a higher strength than annealed steel; it has a relatively high strength and ductility.^[12]
• Quenching: Carbon steel with at least 0.4 wt% C is heated to normalizing temperatures and then rapidly cooled (quenched) in water, brine, or oil to the critical temperature. The critical temperature is dependent on the carbon content, but as a general rule is lower as the carbon content increases. This results in a martensitic structure; a form of steel that possesses a super-saturated carbon content in a deformed body-centered cubic (BCC) crystalline structure, properly termed body-centered tetragonal (BCT), with much internal stress. Thus quenched steel is extremely hard but brittle, usually too brittle for practical purposes. These internal stresses cause stress cracks on the surface. Quenched steel is approximately three to four (with more carbon) fold harder than normalized steel.^[13]
• Martempering (Marquenching): Martempering is not actually a tempering procedure, hence the term "marquenching". It is a form of isothermal heat treatment applied after an initial quench of typically in a molten salt bath at a temperature right above the "martensite start temperature". At this temperature, residual stresses within the material are relieved and some bainite may be formed from the retained austenite which did not have time to transform into anything else. In industry, this is a process used to control the ductility and hardness of a material. With longer marquenching, the ductility increases with a minimal loss in strength; the steel is held in this solution until the inner and outer temperatures equalize. Then the steel is cooled at a moderate speed to keep the temperature gradient minimal. Not only does this process reduce internal stresses and stress cracks, but it also increases the impact resistance.^[14]

• Quench and tempering: This is the most common heat treatment encountered, because the final properties can be precisely determined by the temperature and time of the tempering. Tempering involves reheating quenched steel to a temperature below theeutectoid temperature then cooling. The elevated temperature allows very small amounts of spheroidite to form, which restores ductility, but reduces hardness. Actual temperatures and times are carefully chosen for each composition.^[15]

• Austempering: The austempering process is the same as martempering, except the steel is held in the molten salt bath through the bainite transformation temperatures, and then moderately cooled. The resulting bainite steel has a greater ductility, higher impact resistance, and less distortion. The disadvantage of austempering is it can only be used on a few steels, and it requires a special salt bath.^[16]

• Carbon steel, also called plain-carbon steel, is steel where the main interstitialalloying constituent is carbon. The American Iron and Steel Institute (AISI) defines carbon steel as: "Steel is considered to be carbon steel when no minimum content is specified or required for chromium, cobalt, molybdenum, nickel, niobium, titanium,tungsten, vanadium or zirconium, or any other element to be added to obtain a desired alloying effect; when the specified minimum for copper does not exceed 0.40 percent; or when the maximum content specified for any of the following elements does not exceed the percentages noted: manganese 1.65, silicon 0.60, copper 0.60."^[1]

  The term "carbon steel" may also be used in reference to steel which is not stainless steel; in this use carbon steel may include alloy steels.

  As the carbon content rises, steel has the ability to become harder and stronger throughheat treating, but this also makes it less ductile. Regardless of the heat treatment, a higher carbon content reduces weldability. In carbon steels, the higher carbon content lowers the melting point.^[2]

  Contents [hide] 1 Types 1.1 Mild and low carbon steel 1.2 Higher carbon steels 2 Heat treatment 3 Case hardening 4 See also 5 References 6 Bibliography

  [edit]Types

  See also: SAE steel grades

  Carbon steel is broken down in to four classes based on carbon content:

  [edit]Mild and low carbon steel

  Mild steel is the most common form of steel because its price is relatively low while it provides material properties that are acceptable for many applications. Low carbon steel contains approximately 0.05–0.15% carbon^[1] and mild steel contains 0.16–0.29%^[1] carbon; therefore, it is neither brittle nor ductile. Mild steel has a relatively low tensile strength, but it is cheap and malleable; surface hardness can be increased through carburizing.^[3]

  It is often used when large quantities of steel are needed, for example as structural steel. The density of mild steel is approximately 7.85 g/cm³ (7850 kg/m³ or 0.284 lb/in³)^[4] and the Young's modulus is 210,000 MPa (30,000,000 psi).^[5]

  Low carbon steels suffer from yield-point runout where the material has two yield points. The first yield point (or upper yield point) is higher than the second and the yield drops dramatically after the upper yield point. If a low carbon steel is only stressed to some point between the upper and lower yield point then the surface may develop Lüder bands.^[6]

  [edit]Higher carbon steels

  Carbon steels which can successfully undergo heat-treatment have a carbon content in the range of 0.30–1.70% by weight. Trace impurities of various other elements can have a significant effect on the quality of the resulting steel. Trace amounts of sulfur in particular make the steel red-short. Low alloy carbon steel, such as A36 grade, contains about 0.05% sulfur and melts around 1426–1538 °C (2599–2800 °F).^[7] Manganese is often added to improve the hardenability of low carbon steels. These additions turn the material into alow alloy steel by some definitions, but AISI's definition of carbon steel allows up to 1.65% manganese by weight.

  Medium carbon steel

  Approximately 0.30–0.59% carbon content.^[1] Balances ductility and strength and has good wear resistance; used for large parts, forging and automotive components.^[8]

  High carbon steel

  Approximately 0.6–0.99% carbon content.^[1] Very strong, used for springs and high-strength wires.^[9]

  Ultra-high carbon steel

  Approximately 1.0–2.0% carbon content.^[1] Steels that can be tempered to great hardness. Used for special purposes like (non-industrial-purpose) knives, axles or punches. Most steels with more than 1.2% carbon content are made using powder metallurgy. Note that steel with a carbon content above 2.0% is considered cast iron.

  [edit]Heat treatment

  

  

  Iron-carbon phase diagram, showing the temperature and carbon ranges for certain types of heat treatments.
  Main article: Heat treatment

  The purpose of heat treating carbon steel is to change the mechanical properties of steel, usually ductility, hardness, yield strength, or impact resistance. Note that the electrical and thermal conductivity are slightly altered. As with most strengthening techniques for steel,Young's modulus is unaffected. Steel has a higher solid solubility for carbon in the austenitephase; therefore all heat treatments, except spheroidizing and process annealing, start by heating to an austenitic phase. The rate at which the steel is cooled through the eutectoidreaction affects the rate at which carbon diffuses out of austenite. Generally speaking, cooling swiftly will give a finer pearlite (until the martensite critical temperature is reached) and cooling slowly will give a coarser pearlite. Cooling a hypoeutectoid (less than 0.77 wt% C) steel results in a pearlitic structure with α-ferrite at the grain boundaries. If it is hypereutectoid (more than 0.77 wt% C) steel then the structure is full pearlite with small grains of cementite scattered throughout. The relative amounts of constituents are found using the lever rule. Here is a list of the types of heat treatments possible:

  • Spheroidizing: Spheroidite forms when carbon steel is heated to approximately 700 °C for over 30 hours. Spheroidite can form at lower temperatures but the time needed drastically increases, as this is a diffusion-controlled process. The result is a structure of rods or spheres of cementite within primary structure (ferrite or pearlite, depending on which side of the eutectoid you are on). The purpose is to soften higher carbon steels and allow more formability. This is the softest and most ductile form of steel. The image to the right shows where spheroidizing usually occurs.^[10]
  • Full annealing: Carbon steel is heated to approximately 40 °C above Ac₃ or Ac₁ for 1 hour; this assures all the ferrite transforms into austenite (although cementite might still exist if the carbon content is greater than the eutectoid). The steel must then be cooled slowly, in the realm of 38°C (68.4°F) per hour. Usually it is just furnace cooled, where the furnace is turned off with the steel still inside. This results in a coarse pearlitic structure, which means the "bands" of pearlite are thick. Fully-annealed steel is soft andductile, with no internal stresses, which is often necessary for cost-effective forming. Only spheroidized steel is softer and more ductile.^[11]
  • Process annealing: A process used to relieve stress in a cold-worked carbon steel with less than 0.3 wt% C. The steel is usually heated up to 550–650 °C for 1 hour, but sometimes temperatures as high as 700 °C. The image rightward shows the area where process annealing occurs.
  • Isothermal annealing: It is a process in which hypoeutectoid steel is heated above the upper critical temperature and this temperature is maintained for a time and then the temperature is brought down below lower critical temperature and is again maintained. Then finally it is cooled at room temperature. This method rids any temperature gradient.
  • Normalizing: Carbon steel is heated to approximately 55 °C above Ac₃ or Ac_m for 1 hour; this assures the steel completely transforms to austenite. The steel is then air-cooled, which is a cooling rate of approximately 38 °C (68 °F) per minute. This results in a fine pearlitic structure, and a more-uniform structure. Normalized steel has a higher strength than annealed steel; it has a relatively high strength and ductility.^[12]
  • Quenching: Carbon steel with at least 0.4 wt% C is heated to normalizing temperatures and then rapidly cooled (quenched) in water, brine, or oil to the critical temperature. The critical temperature is dependent on the carbon content, but as a general rule is lower as the carbon content increases. This results in a martensitic structure; a form of steel that possesses a super-saturated carbon content in a deformed body-centered cubic (BCC) crystalline structure, properly termed body-centered tetragonal (BCT), with much internal stress. Thus quenched steel is extremely hard but brittle, usually too brittle for practical purposes. These internal stresses cause stress cracks on the surface. Quenched steel is approximately three to four (with more carbon) fold harder than normalized steel.^[13]
  • Martempering (Marquenching): Martempering is not actually a tempering procedure, hence the term "marquenching". It is a form of isothermal heat treatment applied after an initial quench of typically in a molten salt bath at a temperature right above the "martensite start temperature". At this temperature, residual stresses within the material are relieved and some bainite may be formed from the retained austenite which did not have time to transform into anything else. In industry, this is a process used to control the ductility and hardness of a material. With longer marquenching, the ductility increases with a minimal loss in strength; the steel is held in this solution until the inner and outer temperatures equalize. Then the steel is cooled at a moderate speed to keep the temperature gradient minimal. Not only does this process reduce internal stresses and stress cracks, but it also increases the impact resistance.^[14]
  • Quench and tempering: This is the most common heat treatment encountered, because the final properties can be precisely determined by the temperature and time of the tempering. Tempering involves reheating quenched steel to a temperature below theeutectoid temperature then cooling. The elevated temperature allows very small amounts of spheroidite to form, which restores ductility, but reduces hardness. Actual temperatures and times are carefully chosen for each composition.^[15]
  • Austempering: The austempering process is the same as martempering, except the steel is held in the molten salt bath through the bainite transformation temperatures, and then moderately cooled. The resulting bainite steel has a greater ductility, higher impact resistance, and less distortion. The disadvantage of austempering is it can only be used on a few steels, and it requires a special salt bath.^[16]

Steel,

Steel is an alloy that consists mostly of iron and has a carbon content between 0.2% and 2.1% by weight, depending on the grade. Carbon is the most common alloying material for iron, but various other alloying elements are used, such as manganese, chromium,vanadium, and tungsten.^[1] Carbon and other elements act as a hardening agent, preventingdislocations in the iron atom crystal lattice from sliding past one another. Varying the amount of alloying elements and the form of their presence in the steel (solute elements, precipitated phase) controls qualities such as the hardness, ductility, and tensile strength of the resulting steel. Steel with increased carbon content can be made harder and stronger than iron, but such steel is also less ductile than iron.

Alloys with a higher than 2.1% carbon content are known as cast iron because of their lowermelting point and good castability.^[1] Steel is also distinguishable from wrought iron, which can contain a small amount of carbon, but it is included in the form of slag inclusions. Two distinguishing factors are steel's increased rust resistance and better weldability.

Though steel had been produced by various inefficient methods long before the Renaissance, its use became more common after more-efficient production methods were devised in the 17th century. With the invention of the Bessemer process in the mid-19th century, steel became an inexpensive mass-produced material. Further refinements in the process, such asbasic oxygen steelmaking (BOS), lowered the cost of production while increasing the quality of the metal. Today, steel is one of the most common materials in the world, with more than 1.3 billion tons produced annually. It is a major component in buildings, infrastructure, tools, ships, automobiles, machines, appliances, and weapons. Modern steel is generally identified by various grades defined by assorted standards organizations.

Brief History of Steel.

To understand metals, start with iron. As a basic chemical element Fe, iron is the most abundant metal on Earth. For many centuries, iron furnaces have heated limestone and iron ore that was excavated from the ground. The intense heat melts the both the rock and iron ore, along with several chemical reactions and the lighter liquid rock rises to the top and the heavier liquid iron sinks, creating pig iron. This pig iron is an intermediate step on the way to a final product.

Historically, wrought iron was a building product made from this pig iron. The wrought iron was mostly pure iron (with some slag and small amounts of carbon added). Wrought iron was actually “wrought” (i.e. worked or hammered) into bars and has been used as a construction material for thousands of years. Wrought iron is tough and ductile, easy to weld. Lacking the carbon content for tempering, wrought iron is not hard enough to hold a good edge for a tool or weapon.

Other final products from the pig iron are alloys. An alloy is a combination of two or more elements, in which at least one is a metal. Most metals used for construction purposes are alloys. For example, steel is an alloy with iron and carbon being the primary elements. Generally, iron-carbon alloys with up to 2.1% carbon by weight are considered steel and iron-carbon alloys with greater amounts of carbon are cast iron.

Cast iron is made by re-melting pig iron in a blast furnace, removing undesirable elements like phosphorus and sulfur, adjusting carbon levels and adding other elements. The resulting alloy, commonly called grey cast iron, has a high corrosion resistance and strong compressive strength, but tends to be brittle and difficult to weld. Historically, cannons and cannon balls were made from grey cast iron, as well as some early bridges.

Steel is an alloy that finds tremendous number of uses in today’s construction world. Hot rolled steel shapes, most commonly found as steel beams and columns on construction projects, are created in steel mills by rolling the heat steel between large rollers, deforming the steel into the typical shapes: W, S, C, angles, tube sections, pipes, etc. Most hot formed steel is either 36,000 psi or 50,000 psi yield strength.

Steel in Commercial Construction.

Steel has become a universal building product due to its strength, versatility, durability and economic value. Among its most popular uses today are standing seam metal roofs.

Standing seam metal roofs are fast becoming the material of choice for countless structures. In fact, according to the American Iron and Steel Institute, the roofing system has been used in nearly 50% of all low-rise commercial, industrial and institutional buildings erected in the last several years. Standing seam metal roofing can now be seen on virtually every type of building, from shopping centers and schools to churches and libraries. The system currently accounts for well over one billion square feet.

This acceptance has carried over to the re-roofing market where standing seam roofs have been used successfully as replacements for built-up and single ply systems.

In retrofit projects where costly tear-offs want to be avoided, a sub-framing system is attached to the existing roof surface to provide a minimum ¼:12 pitch for the new metal roof.

Steel Provides Aesthetic Appeal, Long Service Life

The use of metal roofing is growing rapidly because steel offers a variety of benefits. One is its aesthetic appeal. The standing seam roof is one of the most attractive roofing systems for almost any building. It is available in a wide range of finishes, color and profiles, providing building owners and architects with extensive design flexibility.

Another of metal roofing’s benefits is its long service life. As a result of the zinc, aluminum, or aluminum-zinc alloy metallic coating applied to the base steel, today’s metal roof panels resist corrosion and provide a service life of 20 years or more of trouble-free performance, considerably longer than the standard protection for built-up and single ply systems.

Steel Roof Is Cost Effective, Energy Efficient

Metal roofs are also very cost effective. Standing seam steel roofs pay for themselves from the day they are installed. Their life expectancy is long, they require little or no maintenance, and their life cycle costs are low, especially compared to non-metal alternatives in low slope applications.

Metal roofs are also energy efficient, especially when used in “cool roof” applications. Cool metal roofs feature heat-deflecting coatings that decrease unwanted heat build-up inside a building, thereby reducing cooling loads. Based on research on cool metal roofing, the reflectivity and emissivity of steel roofs have been proven to provide significant savings in energy consumption.

Environmental Benefits of Steel Are Many

While building owners and architects have long recognized steel for its strength, durability and functionality, they are now increasingly recognizing another of steel’s important attributes – its environmental benefits.

The recycled content for steel used in metal roofs and walls, for example, is at least 25%. This level of recycled content reduces both the cost and environmental impact of making new steel, as it conserves energy and other natural raw materials.

The fact that the recycled content of steel is at least 25% by weight helps earn points in the U.S. Green Building Council’s Leadership in Environmental and Energy Desgin (LEED) program. Steel’s recycled content is especially important when it is compared to other materials such as concrete, which has a recycled content of only 3% (fly ash) and even less when the weight of the recycled material is factored in.

Steel Is 100% Recyclable at End of Useful Life

Steel is also 100% recyclable at the end of its long, useful life. In fact, of the metals used in roofs and walls, steel is the most recycled. Easily separated from other materials via magnetics, steel is reclaimed through a vast collection and processing network.

Every ton of steel recycled saves over 4,000 pounds of raw materials, including 2,500 pounds of iron ore, 1,400 pounds of coal and 120 pounds of limestone. And, according to the EPA, new steel made with recycled material uses as little as 26% of the amount of energy that would be required to make steel from iron and other materials extracted from nature. In addition, the original embodied energy of steel products is amortized as steel is recycled again and again into new steel products.

Improve Your Body Language

Body language and gestures makes the first impression of your personality as you socialize. Try out these simple tips to improve your body language and get social.

They say that the first impression is the last impression. Your body language and your gestures make that first impression of yours every time you meet someone for the first time.

Making a good impression on anyone is the first thing that one should think of before meeting someone. Whether you meet someone individually or in a group, your body language and gestures tell about grooming and background.

• Improve your Body Language

The first and foremost rule to improve your body language is to be natural. Don’t boast to be nice and polite, rather be nice to everyone naturally. This would send out positive energy to the other person and you surely will receive the same in return because he/she would be happy to see you this way.

• Standing and Sitting Posture

Keep your posture straight while standing or sitting. Keep your legs and arms in right position so that you don’t look uncivilized.

• Use of Hands

Make less use of your hands while talking. Swinging your hands all the time while talking makes you feel uncomfortable and confused about what you are talking about.

• Use Eyes

Try to convey the message through your eyes. Use your eyes to express your say. This will make a great impression on the listener(s). They would become more attentive towards you. Creating gestures through eyes implies that you are intelligent and confident about your opinions.

• Practice in Front of Mirror

Another way to improve your body language is to practice in front of the mirror everyday for a few minutes. This will make you understand your body gestures and will make it easier for you to convey.

• Neck Position

Always keep your neck in an upright position. It really makes an impression on the listener(s). Always keep your say to the point, simple and easy to understand. Keep your tone low so as not to give an impression as if you want to dominate the others.

The art of body language and gestures is the most important thing in your personality. Improving it can only be achieved through practice. So keep a note of these points as you socialize in the society

- Movie Review.

Dear John, yet another adaptation of one of Nicholas Spark`s novels has all the ingredients of a romantic tearjerker; love, loss and separation. The story revolves around a star crossed couple, college student Savannah (Amanda Seyfried) and Special Forces soldier John (Channing Tatum) who meet on a South Carolina beach in early 2001 and fall head over heels in love. They promise to write regularly, until John returns in a year.

And so the journey begins, and as with any romantic movie, with ups and downs, though the ups are far and few while the obstacles keep on mounting, one after the other. The first is John’s re-enlistment after 9/11, which leaves Savannah alone and worried. The second is the inevitable Dear John letter, in which she tells her soul mate that she is about to marry someone else.

At times the actions of the characters fail to make sense and the only reason for you to continue watching the movie avidly is your complete faith in Nicholas Spark`s ability to twist a tale and sprinkle it with coincidences, impulsive actions and sometimes, simple faith. While Ryan Gosling played the role of a romantic hero to perfection in The Notebook, Tatum Channing`s performance leaves a lot to be desired. His good looks are his only saving grace. Amanda Seyfried on the other hand is perfect as Savanah, the idealistic college student and brings spunk to her role. All in all, the chemistry between the two is strong enough to keep you glued to the seat till the end. The supporting cast also holds its own against the main leads and in fact their existence is what helps to explain why Savanah and John do the things they do and think the way they do.

As is the case with all of Nicholas Spark`s adaptations, the soundtrack of Dear John is simply splendid, complimenting the movie and its characters. Paperweight and Set the fire to the third bar are part of the main soundtrack and aptly depict the situation and dilemmas the couple is facing.

All in all, it is a mediocre movie laced with romance, desperation and loss. Dear John is definitely not an Oscar winner but if you`re looking for a little escapism, bring your tissues and enjoy!