12 METAL WORKS

METAL WORKS

Metalworking -is the process of working with metals to create individual parts, assemblies, or large scale structures.
Metalworking- is a science, art, hobby, industry and trade. Its historical roots span cultures, civilizations, and millennia. Metalworking has evolved from the discovery of smelting various ores, producing malleable and ductile metal useful for tools and adornments. Modern metalworking processes, though diverse and specialized, can be categorized as forming, cutting or joining processes. Today's machine shop includes a number of machine tools capable of creating a precise, useful workpiece.

Metal Rod and Bar Stock

Metal rod and bar stock are metals and alloys in the form of round bars or rod, square bars, rectangular or flat bars, hexagons, and other bar stock shapes. These shapes are also available in billet form and typically included a cross-section based on the shape of the rod or bar stock. Reinforcing bars may also be included; these bars are included to strengthen or internally support concrete and masonry structures. Other metal rod and bar stock forms include coil stock and hollow tube stock.

Welding is a hazardous activity that poses safety and health risks if precautionary measures are not followed. One effective way of preventing accidents when working with welded materials is by wearing the proper welding attire.

Types of Rod Bars

• square bar
• round bar stock
• rectangular bar
• hex bar stock
• reinforcing bar

ESSENTIALS FOR PROPER WELDING PROCEDURES

1. Correct electrode size
2. Correct current
3. Correct arc length or voltage
4. Correct travel speed
5. Correct electrode angle

Besides the steady sizzling sound that a correct arc produces the shape of the molten pool and the movement of the metal at the rear of the pool serve as a guide in checking weld quality. In a correctly made deposit the ripples produced on the bead will be uniform and the bead will be smooth no overlaps or undercuts.

1. CORRECT ELECTRODE SIZE
   The correct choice of electrode size involves consideration of a variety of factors, such as the type, position, preparation of the joint, the ability of the electrode to carry high current values without injury to the weld metal or loss of deposition efficiency, the mass of work metal and its ability to maintain its original properties after welding, the characteristics of the assembly with reference to effect stresses set up by heat application, the practicability to heat treatment before and / or after welding, the specific requirement before and / or after welding, the specific requirements as to welding quality and cost of achieving the desired results.
   
   
2. CORRECT CURRENT
   If current on equipment is too high or too low, you are certain to be disappointed in your weld. If too high, the electrode melts too fast and your molten pool is large and irregular, if too low, there is nor enough heat to melt the base metal and your molten pool will be small, will pile up, look irregular.
   
   
3. CORRECT ARC LENGTH
   If the arc is too long or voltage too high the metal melts off the electrode is large globules which wobble from side to side as the arc wavers, giving a wide, spattered and irregular bead-with poor fusion between original metal and deposited metal.
   
   If the arc is too short, or voltage too low, there is not enough heat to melt the base metal properly and the electrode quite often sticks to the work, giving a high, uneven bead, having irregular ripples with poor fusion.
   
   
4. CORRECTTRAVEL SPEED
   When your speed is too fast your pool does not last long enough, impurities an gas locked in. The bead in narrow and ripples pointed. When speed is too slow the metal piles up, the bead is high and wide with a rather straight ripple.
   
   
5. CORRECT ELECTRODE ANGLE
   The electrode angle is of particular importance in fillet welding and deep groove welding. Generally speaking, when making a fillet weld, the electrode should be held so that ir bisects the angle between the plates (as shown at right) and is perpendicular to the line of weld, if under cut occurs in the verticle member, lower the angle of the arc and direct the arc toward the vertical member.

PLATE

Steel plates come in various material composition to suit specialized uses.

The common industrial names of the different plates are:

• Ship Plates
• Boiler Plates
• Mild Steel Plates
• Checkered Plates, etc

Weight and dimensions of Ship, Boiler and MS plates are uniform to facilitate ordering.

Steel chequered plates are available in either the direction-free riser pattern or the straight striped pattern.

Since they feature excellent skid resistance and relatively low weight per unit area, these plates are economical to use in flooring and other structural applications.

CHECKERED PLATES

Steel checkered plates are available in either the direction-free riser pattern or the straight striped pattern.

Since they feature excellent skid resistance and relatively low weight per unit area, these plates are economical to use in flooring and other structural applications.

CHANNELS

Mild Steel Channels are used mainly in heavy industries. MS Channels are usually applied in the automotive industry as well as heavy machinery industries.

Generally, there are 3 types of mild steel channel, they are:

• Plain Channels
• Lipped Channels
• U/C Channels

ROUND BARS

Round Bars fulfill a large number of uses. Because of its intrinsic strength, which stems from its circular cross section, round bars offer universal applications where omni directional strength is of premium, especially in the reinforcement of concrete.

Round bars come in 2 varieties, both having identical measurements:

• Brightshaft Round Bars
• Mild Steel Round Bars

FLAT BARS

Flat Bars may be considered the most basic of steel structures. It is milledin a wide variety of dimensions. It’s applications range from construction to machinery fabrication.

ANGLE BARS

Angle Bars are one of the most commonly used steel structures in the construction industry. The basic shape of the Angle Bar lends it many practical uses.

There are basically 2 types of Angle Bars, namely:

• Equal Angle Bars
• Unequal Angle Bars

FLOOR GRATINGS

Gratings are usually used as extremely durable metal industrial floors. Common applications are in oilrig constructions.

Gratings come in 2 forms, namely Serrated Bearing Bar (flat) with Twisted Transverve Bar and Serrated Bearing Bar (flat) with Plain Round Bar. Gratings have also the options of being galvanized for weatherproofing needs.

PIPES

Pipes have played an important role in the advancement of civilization. Clay pipes were used over 5,000 years ago in ancient Babylon.

With man’s progress came the advent of electrically welded steel pipes. Thanks to modern science and technology, strong and extremely durable steel pipes are available for everyday applications.

There are 4 classes of pipes:

• Welded Steel Pipes – Class Light
• Welded Steel Pipes – Class Medium
• Welded Steel Pipes – Class Heavy
• Carbon Steel Pipes