8 Common Source Of a Wet Basement and Finding The Cause Before You Begin Basement Waterproffing

Moisture problems in a basement stem from one of two sources: indoor condensation or leaks from outdoors. You can usually determine whether the source of your problem is interior or exterior by performing this simple test.

Once you know which side of the basement wall the moisture is coming from, you still need to identify a specific source. That can be a little tricky, but here are the most common culprits:

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1. Downspouts

Downspouts should direct water away from the house foundation with extensions that are at least 6-feet long.

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2. Gutters

Gutters are supposed to carry water to downspouts, but when they become clogged they can cause water to overflow. That means water is being dumped along the basement walls.

3. Grading

Improper grading is a major cause of wet basements. In the first 10 feet around the foundation, the soil should slope at least 6 inches away from the house.

4. Foundations

Over time, foundations can develop cracks that allow water to flow through. Hydraulic cement is a useful product for sealing masonry walls.

5. Plumbing

Water supply and drain pipes can leak. Drain lines in particular can develop small, hard-to-detect leaks that can cause long-term trouble. You should be able to find a drain line leak by turning all of the faucets in the house on and then doing a close visual inspection of the pipes in the basement.

6. Windows and Doors

Broken glass or aging seals around windows and doors allow easy access for water. Have someone spray water from a hose at basement windows and doors while you look for leaks inside.

7. High Humidity

A basement that is moist most of the time usually has some type of condensation problem. You can tackle the most common causes by following the advice in this article.

8. High Water Table

This is one of the toughest wet basement challenges. The water table is the line between saturated and unsaturated soil. It can vary by season and location, and even a heavy rainfall can cause the water table to rise. There's not much you can do to change the water table, but you can reduce its damaging effects with interior or exterior drainage systems or with a sump pump.

Installing a Sump pum,Types of Sump Pump, Digging a Sump Pit

Installing a sump pump can be an effective way to keep water from accumulating in the basement. The pump is set in a basin, or sump pit, located at the lowest spot in the basement floor or where water first accumulates. Sump pits, which can be purchased at home centers, are most often made of plastic or fiberglass. As the water level beneath the basement floor rises, it fills the pit, activating the pump and causing the water to be discharged to the outdoors. Once the water level falls, the pump shuts off.

If your basement has occasional water problems, a sump pump can be an inexpensive and relatively easy-to-install aid. But keep in mind that installing a sump pump will not address the source of your water problem. So, before you spend any time and money on pumping water out of the basement, take a few moments to learn about the 8 Common Sources of a Wet Basement.

And if your basement is seriously flooded on a regular basis, a sump pump may not be the best solution. After looking at sources of your water problem, you may want to consider these 3 Approaches to Basement Waterproofing.

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Types of Sump Pumps

There are two types of sump pumps usually installed in houses: submersible pumps are fully concealed in the sum pit, while pedestal pumps are only partially concealed, with the motor resting above the water. Pedestal sump pumps tend to cost a bit less than submersible models, and they are easier to repair and maintain. But submersible pumps are quieter, and therefore a better choice for living areas.

Sump pumps usually come with long cords, allowing you to plug them into a receptacle protected by a ground fault circuit interrupter (GFCI). Do not use an extension cord with a sump pump unless it matches the recommendations of the pump manufacturer.

Plumbers can usually install sump pumps, but a motivated DIYer can also handle the job. If you want to install your own sump pump, plan to spend $300-$500 for materials and the better part of a weekend for the installation.

Digging a Sump Pit

You will need a jackhammer to break through the concrete. Electric jackhammers are usually available at rental stores or in the tool rental department at home stores. They are easy to use and can be plugged into regular household outlets. Be sure to get a flat spade bit to use with the jackhammer.

Set your sump basin upside down on the floor, then draw a circle about 4 to 6 inches outside the perimeter of the basin. Be sure to stay at least 10 inches from the walls to avoid the foundation footing. Use the jackhammer to break through the slab along the line.

With the concrete out of the way, dig the hole to the required depth. You want the top of the basin flush with the top of the floor. Set the basin in the hole and fill the gaps around the perimeter with gravel. Level the gravel 1 inch above the bottom of the floor slab, then fill the remainder of the perimeter gap with concrete. Smooth the surface of the concrete with a trowel and allow to set for at least a day.

Installing the Sump Pump

Once the concrete has cured, set the sump pump in the basin as directed by the manufacturer. Connect the check valve and attach PVC discharge piping. Run the piping up the wall and out through a hole you drill in the rim joist.

Extend the piping to the outside, allowing water to drain away from the foundation. If the grade is not suitably sloped away from the house, you may need to install a drywell outside for the discharge piping to empty into. Do not run discharge into sewer or septic systems unless you are sure this is permitted by local building codes.

Seal around hole in rim joist with caulk. Now plug the sump pump into a GFCI receptacle. Fill the basin with water and test the pump.

From time to time you will need to clean debris out of the basin, and if your pump is not activated very often, periodically test it by pouring some water in the basin.

safety Goggle : What Is Main A Braker

So, what is a main breaker anyway? You'd think that it is something special having a name like that. Actually, the main breaker is the breaker that the feeder wire connects to. This breaker is a two-pole breaker that is connected to 240 volts to power your home. The main breaker acts as the disconnecting means to the entire power load of your breaker box. With it off, there is no power being fed to the buss bar that feeds the branch circuit breakers.

The main breaker is usually located atop the rest of the breakers in a panel, but sometimes the breaker panel is installed upside down. In this case, the main would be at the bottom. Some main breakers are bolted in place and others are snapped into place just like the branch circuit breakers.

Main breakers come in different sizes, but 100 and 200-amp breakers are generally used in residential installations. In older homes, you may still have a 60-amp service and I personally have seen a 30-amp, 120-volt main service. If you think you are short on power, think about that installation!

Main breakers are designed to trip if the amperage rating exceeds the value labeled on the breaker. For instance, if you have a 100-amp main breaker in place, if the amperage exceeds 100 amps, the breaker will trip.

There are a number of reasons why breakers trip. It may be lightning strikes, power surges from the utility company, or you may have overloaded your electrical panel.

If your electrical panel's main breaker does trip, turn off the branch circuit breakers before resetting the main breaker. Then, one at a time, start turning on breakers again. The idea here is not to dump the entire power load on the main breaker all at once. If the breaker trips again, you may be well advised to call in a professional.

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Operating a Bulldozer Requires Special Safety Rules

Operating a Bulldozer Requires Special Safety Rules

The bulldozer was invented primarily for farm work such as ploughing fields. It has become more powerful and sophisticated with time and modernization of heavy equipment. Learning to handle this giant earthmover requires the operator to know certain safety rules to keep everyone safe.

If you haven’t seen a bulldozer, than you may not realize the massive size of this heavy equipment. This monster machine’s pure size, if not operated correctly, can cause injury and even death to the operator, the ground crew and destruction to anything else in its way — including other equipment.

We all heard about general heavy equipment safety tips but there are safety rules that need to be followed specifically for the bulldozer.

Bulldozer safety tips :

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Only qualified and trained drivers should operate a bulldozer. This isn’t an equipment anybody with can just hop in and operate. In fact, if there is just one bulldozer operator on the team, than he or she should be the sole operator — no substitutions even if the need may arise.

Common sense safety steps such as wearing a safety belt need to be followed. A safety belt may just save you from head injury.

Before attempting to work, operators must make sure nothing is obstructing the area and that the machine and all parts are working properly. The horn is one thing that should be tested.

Communication and inspection of the bulldozer area work site is extremely important. Operators should coordinate with the traffic department and make sure there is a lead person who will control and take responsibility of the traffic while work is in progress. Road blocks or flagman can be utilized to keep areas safe for bulldozer use.

Bulldozer operators should get in the habit of looking up when conducting inspections. This is because bulldozers can actually run into overhead power lines that might cause a possible accident. This is the same for looking below since a trench or an excavation area can cause mechanical and structural damage to the equipment as well as possible risk for injury to the operator

Safety is important in handling any kind of equipment, but specific safety tips should be followed for the bulldozer operator. A good professional heavy equipment school can help you learn about those tips and rules. Learning the important of safety before getting in the driver’s seat can save a life — maybe yours.

Application Of Precision Stampings

Precision stamping is a fast and cost-effective solution for manufacturing large quantities of complex products. There are three major precision stamping applications currently in use at factories across the globe: micro-precision stamping, intricate precision metalwork, and prototype design.

Metal stamping uses high tonnage presses and stamping dies to forge sheets of metal into complete or semi-complete parts. Precision metal stamping improves the speed and accuracy of complex stamping applications by allowing the stamping, folding, drawing, or piercing of a product in a single or series operations.

Benefits and Disadvantages Of Precision Stamping

Precision stamping can be highly automated, making the process well-suited for high-volume because labor costs drop as production levels increase. Upfront tooling costs, however, may render precision stamping ineffective for smaller production runs. Other factors to consider include long lead times and difficulty making design changes once the tools have been created.

What Is Micro Precision Metal Stamping?

Micro-precision stamping is capable of making minute stamps, cuts, bends, and folds in a workpiece. Typically, micro-precision stamping machines support tools with diameters on the micron level. Minimum diameter capabilities vary depending on the particular machine, but .002 inches and .005 inches are common minimum specifications. These micro-stamping combine photo etching technology and 3D computer software to perform highly exact operations.

Benefits of Micro Precision Thin Material

Aside from its effectiveness in manufacturing small parts, precision micro-stamping provides numerous other advantages. Some of these include:

Reduced risk: The inclusion of modular and digital tooling reduces tooling costs. Quick results: Thanks to decreased tooling barriers, production can be finished within days. Improved flexibility: Changes in product designs are less costly or time consuming than with traditional precision stamping methods.

Intricate Precision Metal Work

Complex products or innovative designs sometimes require a more sophisticated precision stamping procedure. When this is the case, manufacturers often seek out a stamping company that specializes in complex or intricate precision metalwork. These companies will have the considerable experience and advanced technologies necessary for fabricating products with intricate geometries, cuts, folds, or engravings with exact specifications. Some of the technologies that make intricate precision metal working possible include:

In-die extrusion and tapping: Extrusion and tapping are both performed in the same die to eliminate the need for a weld nut Progressive die design: This method applies sophisticated software to improve the die development. Deep draw stampings: Deep drawing allows the formation of 3D shapes, such as squares, cylinders, and shells. Transfer stamping: This technique reduces costs and secondary operations when stamping complex geometries. Class A dies: These dies deliver increased accuracy over steel rule dies. Magnified optical devices: Magnified optical devices provide more precise grinding results.

Applications of Intricate Precision Metal Work

Many industries require that produce complex components may benefit from intricate precision metal stamping. Some products routinely fabricated with the help of complex precision stamping techniques include:

Automotive engines Aircraft components Machine gears Complex electronics Telecommunication products

Prototype Design and Precision Stamping

Many precision stamping companies offer prototype design service without the need for expensive dedicated tooling. This helps make prototype design and production cost-effective prior to committing to a final design. Computer programming the stamping equipment also improves the turnaround time. While traditional techniques may take days or weeks to manufacture upfront tooling devices, a company that specializes in prototype design can often deliver same-day or next-day results.

Types of Prototype Design

Prototypes are manufactured through two main processes: single-part transfer and progressive strip prototyping. These processes entail:

Single-part transfer prototyping: In this process, individual prototype parts are manually moved from station to station. At each station, the part is blanked or metal formed. The main advantage of this method is reduced tooling costs at warehouses that maintain a standard system for design. The disadvantages of single-part transfer include high parts costs and the inability to incorporate miniature parts or complex feature tolerances.

Progressive strip prototyping: This method differs from single-part transfer in that a progressive die guides the contained stock prototype material through each step in the design process. At each station, the die completes an operation and delivers a complete product at the final stage. Movement of the die along the strip is either manual or controlled by an automatic feeder. Due to increased automation, progressive strip prototyping is good for applications that require miniature part sizes, advanced feature tolerance, and improved production speed.

Die Casting Process Types

Die casting is a popular manufacturing process for casting metal products. There are two main die casting process types and several variations in process design. When molten metal is forced into mold cavities at high pressure, it is known as die casting. The process is best suited for speedy production of bulk metallic parts that require minimal post-production machining. The main benefits of the die casting process include:

High quality: Parts created through die casting deliver a long service life. High reliability: Uniformity of mass-produced parts is exceptional. Quick production: Die cast tooling requires minimal maintenance. Versatile design: Die casting can createvirtually any size, part geometry, surface texture or luster.

Minimal assembly: Assembly features such as studs, drill holes and bosses can be integrated into mold design.

Applications of Die Casting Processes

Die casting is a process that has far-reaching applications. Any part production process that creates high-volume metal components will likely benefit from die casting. A variety of manufacturing industries currently rely on one or many types of die casting processes, including the auto, aerospace and power tools industries. Types of Die Casting Processes

All die casting process types are designed with the same goal in mind—cast a mold using injected molten metal. Depending on the type of melted metal, part geometry and part size, different die casting processes can deliver superior results over alternative methods. The two main types of die casting processes are hot-chamber and cold-chamber die casting. Variations on these two types of die casting include:

Low-pressure die casting Vacuum die casting Squeeze die casting Semi-solid die casting

The Hot-Chamber Die Casting Process

Hot-chamber die casting, sometimes called gooseneck casting, is the more popular of the two die casting processes. In this process, the cylinder chamber of the injection mechanism is completely immersed in the molten metal bath. A gooseneck metal feed system draws the molten metal into the die cavity.

While direct immersion in the molten bath allows for quick and convenient mold injection, it also results in increased corrosion susceptibility. Due to this fact, the hot-chamber die casting process is best suited for applications that utilize metals with low melting points and high fluidity. Good metals for the hot-chamber die casting process include lead, magnesium, zinc and copper. The Cold-Chamber Die Casting Process

The cold-chamber die casting process is very similar to hot-chamber die casting. With a design that focuses on minimizing machine corrosion rather than production efficiency, the melted metal is automatically- or hand-ladled into the injection system. This eliminates the necessity for the injection mechanism to be immersed in the molten metal bath.

For applications that are too corrosive for the immersion design of hot-chamber die casting, the cold-chamber process can be an excellent alternative. These applications include the casting of metals with high melting temperatures, such as aluminum and aluminum alloys.

The Low-Pressure Die Casting Process

Low-pressure die casting is a process best suited for aluminum components that are symmetric around an axis of rotation. Vehicle wheels, for example, are often fabricated through low-pressure die casting. In this type of process, the mold is situated vertically above the molten metal bath and connected via a riser tube. When the chamber is pressurized (usually between 20 and 100kPa), the metal is pulled upward and into the mold. The elimination of feeders from this type of die casting process delivers the high casting yields. The Vacuum Die Casting Process

Vacuum pressure casting (VPC) is a relatively new die casting process that delivers enhanced strength and minimal porosity. This process is similar to low-pressure die casting, except the locations of the die cast mold and molten metal bath are reversed. The cylinder chamber can become a vacuum, which forces the molten metal into the mold cavity. This design reduces turbulence and limits the amount of gas inclusions. Vacuum die casting is especially beneficial in applications destined for post-casting heat treatment. The Squeeze Die Casting Process

Squeeze casting was created as a workable solution for casting metals and alloys with low fluidity. In this process, the molten metal fills up an open die, which then squeezes closed, forcing the metal into the recessed portions of the molding. The squeeze casting process delivers extremely dense products and is a complementary process to subsequent heat-treating. The process is most often associated with molten aluminum, and is used in applications that call for fiber reinforcement. The Semi-Solid Die Casting Process

Semi-solid die casting, sometimes called Thixoforming, is another process that delivers minimal porosity and maximum density. A machine cuts the workpiece into smaller slugs, and then heated. Once the metal has reached the phase transition between solid and liquid, resulting in a somewhat slushy texture, a shot sleeve forces it into the mold cavity, where it hardens. The benefit of this is improved precision. Non-ferrous metals such as magnesium alloy and aluminum alloy are most often used with the semi-solid die casting process.

How Die Casting Alloys Work

How Die Casting Alloys Work Die-casting is a fabrication technique involving high pressure injections of liquefied metal into a cast. It is useful for accurately mass-producing items according to specifications. Many products, such as automobile parts, sink faucets, and connector housings, are created using the process.

Die-casting can be an appealing and cost-effective method for manufacturing sturdy items. When selecting an appropriate fabrication material, there are several factors to consider, including the type of die-casting process to be used and the intended function of the product.

Types of Die-Cast Processes

Two common die-casting methods are the cold-chamber and hot-chamber processes, and distinguishing the proper method largely depends on the size of the finished product and the alloy selected. For example, aluminum is a more efficient choice for the cold-chamber process than it is for the hot-chamber method.

Cold-Chamber Process: Metal is liquefied in a furnace, then ladled into a cold chamber. This technique is often used with metals that alloy quickly with iron at high temperatures, such as copper and aluminum, because these materials would regularly pose problems when melted in a (part-iron) casting machine. The cold-chamber process is better-suited to metals with high melting points.

Hot-Chamber Process: Metal is melted in the casting machine, and fed into the die. The injection method allows metal to be added more quickly, but is ineffective with materials that have high-melting points, such as aluminum-based alloys. Therefore, a hot-chamber process is typically used with tin, lead, or zinc-based alloys. Types of Alloys Used in Die-Castings

Aluminum is commonly employed in die-casting, but is prone to cracking or shrinking at high temperatures, so it is often alloyed with copper or silicon. Combining aluminum with these metals greatly increases its hardiness and fluidity. Since it has high dimensional stability, aluminum is used to create components with thin walls and complex shapes. Due to its corrosion resistance, aluminum is also beneficial in components that will face exposure to thermal or electrical energy.

Copper-based alloys are also commonly employed in die-casting. Many of these alloys are quite durable, making them an effective choice for mechanical products. Due to copper’s very high resistance to corrosion, it is often used to create plumbing and electrical material.

Zinc is relatively easy to cast and maintains high strength at room temperature, but can be alloyed with aluminum to further improve these qualities. Zinc has a lower melting point than aluminum and is suitable for hot-chamber casting. It is also valuable in the manufacture of products that require high precision and sturdiness, such as connectors and gears.

Magnesium has a high strength-to-weight ratio despite being a relatively light alloy, and it is useful for die-casting operations that require thin-structured walls and close precision.

Considerations When Choosing Die-Casting Alloys

The function and use of the final product will dictate die-casting alloy selection. For example, if the component requires high strength and corrosion resistance, an aluminum or copper based alloy could be an effective choice. Another consideration is production volume. With proper maintenance, aluminum die-casts can have a life of approximately 100,000 cycles, while zinc molds can last up to one million cycles before being replaced. For long-term, high-volume production, it may be more cost-effective to use alloys that maximize the life of the molds. When considering various fabrication methods, it may be helpful to examine the advantages and disadvantages of using a die-casting process.

Potential advantages include:

Dimensional Strength: die-cast parts are stronger than plastic components.

Rapid Production: die-cast components can be produced in high volume with relatively little tooling or machining.

Smooth Surfaces: the die-cast process can create finished parts with curved or seamless surfaces.

Accuracy: die-cast parts can be created with close adherence to specifications.

Possible disadvantages include:

High Volume: smaller production runs may reduce cost-effectiveness.

Limited Metal Fluidity: alloy malleability varies, which can limit the complexity and shape of the finished product.

Size and Weight Limits -- A casting machine’s capacity limits the range of product dimensions.

Related Products and Categories Die-casting is used for a variety of consumer, commercial and industrial manufacturing purposes, such as the production of automobile powertrains, engine parts, telecommunications equipment, marine equipment, household appliance parts and hand tools.

There are numerous variants within the die-casting process. Some of the related materials and procedures include:

Single-cavity die: A mold designed to create a single component.

Multiple-cavity die: A mold designed to create several identical parts.

Unit die: A mold designed to create several different parts that are all part of the same component.

Die lubricant: Liquid applied to the interior surfaces of the mold to ensure easy removal of the component.

How to Design a Die Casting Mold

Die casting is a technique for mass-producing metal products and components. Mold design is one of the most important steps in the process because the shape and attributes of the mold will directly affect the final product. The die casting procedure forces molten metal into molds using high pressure and it requires a mold with exact specifications to achieve the task.

The Importance of Mold Design

Mold design affects the shape, configuration, quality, and uniformity of a product created through the die casting procedure. Improper specifications can result in tool or material corrosion, as well as inferior product quality, while an effective design can improve efficiency and production time.

Factors Contributing to Quality Mold Design

There are a number of mold design factors to consider when deciding on the appropriate specifications for a project. Some of these factors include:

Die draft Fillets Parting lines Bosses Ribs Holes and windows Symbols Wall thickness

Draft

Draft is the degree to which a mold core can be tapered. A precise draft is needed to smoothly eject the casting from the die, but since draft is not constant and varies according to the angle of the wall, features such as the type of molten alloy used, shape of the wall, and depth of the mold can affect the process. Mold geometry can also influence draft. In general, untapped holes require tapering, due to the risk of shrinkage. Likewise, inner walls can also shrink, and therefore require more drafting than outer walls.

Fillets

A fillet is a concave junction used to smooth an angled surface. Sharp corners can hinder the casting process, so many molds have fillets to create rounded edges and reduce the risk of production errors. With the exception of the parting line, fillets can be added nearly anywhere on a mold.

Parting Line

The parting line, or parting surface, connects different sections of the mold together. If the parting line is imprecisely positioned or becomes deformed from work strain, material may seep through the gap between the mold pieces, leading to non-uniform molding and excessive seaming.

Bosses

Bosses are die cast knobs that serve as mounting points or stand-offs in mold design. Manufacturers often add a hole to the interior structure of the boss to ensure uniform wall thickness in a molded product. Metal tends to have difficulty filling deep bosses, so filleting and ribbing may be necessary to alleviate this problem.

Ribs

Die cast ribs can be used to improve material strength in products lacking the wall thickness required for certain applications. Selective rib placement can reduce the chance of stress cracking and non-uniform thickness. It is also beneficial for decreasing product weight and improving fill capabilities.

Holes and Windows

Including holes or windows in a die cast mold directly affects the ease of ejecting a completed molding and enables the creation of substantial drafts. Additional features, such as overflows, flashovers, and cross feeders may be necessary to prevent unwanted casting within the holes or poor material flow around the holes.

Symbols

Manufacturers often include brand names or product logos in the mold design of die-cast products. While symbols do not typically complicate the die casting process, their use can affect production costs. In particular, a raised logo or symbol requires additional molten metal volume for each manufactured part. Conversely, a recessed symbol requires less raw material and can reduce expenses.

Stainless Steel Fabricating Processes

Due to its versatility, there are a wide range of stainless steel fabricating techniques. It may be helpful to review some of the processes involved in order to better understand the benefits and disadvantages of the different types of stainless steel fabrication.

Although it has relatively high strength and work hardening rates, stainless steel is malleable enough to be bent, folded, machined, welded, deep drawn, or spun. This guide will focus on three common stainless steel fabricating processes: work hardening, machining, and welding. Work Hardening with Stainless Steel

Work hardening is the process of strengthening material through deformation. Relative to other varieties of steel, stainless steel work hardens quickly, although the exact rate depends on the specific grade of the alloy. The austenitic family of stainless steel, for example, has a hardening rate slightly higher than that of carbon steel and is a frequently used grade series in fabrication processes.

It is also helpful to match the steel grade with a work hardening treatment that is well-suited for it. Since austenitic stainless steel can usually be hardened only through cold working, a thermal treatment process would be better applied to other grades, such as those in the martensitic family. Work Hardening Rates of Stainless Steel

Since ferritic stainless steels yield lower work hardening rates, austenitic and martensitic stainless steels are the series that benefit most from work hardening applications. In some instances, austenitic stainless steel can be cold worked up to 1,000 MPa, although the maximum is typically in the 800 MPa range. When cold drawn, stainless steel may reach tensile properties of 2,000 MPa or greater, but such high strength levels are usually limited to fine wire sizes. Size is a concern due in part to the quick work hardening rate of stainless steel, which yields diminishing tensile strengthening at the core of a wire as its diameter increases.

A fast work hardening rate provides certain benefits, as well. For example, stainless steel’s hardening rate renders the alloy effective in projects that require high strength and corrosion resistance. Common applications include the manufacturing of nuts and bolts, machine parts, cryogenic machinery and hospital equipment. The martensitic group, in particular, displays the highest levels of hardness and corrosion resistance among the stainless steel categories, making it a popular alloy for the production of tools, valve parts, bearings, and cutlery. Other Characteristics of Stainless Steel

Work hardening can also increase the magnetism of stainless steel. While its magnetism tends to be relatively slight, grades with higher work hardening rates exhibit higher levels of magnetic capacity after treatment. Stainless steel also undergoes greater deformation at slower forming speeds, requiring some high-speed forming processes to be slowed down to improve their work hardening efficiency. Machining Stainless Steel

Grades 303, 430, 410 and 416 achieve resistance to chipping when alloyed with manganese sulfide. Due to the decreased ductility and corrosion resistance that comes with the addition of manganese sulfide, these grades have limited machining applications, though several free-machining grades have been developed to address the problem.

To overcome the limits of machining certain types of stainless steel, some companies have incorporated exclusive steel melting techniques to improve the machinability of commonly-used austenitic grades. These specialized processes can improve machining efficiency, and may contribute to longer tool life. Tips on How to Machine Stainless Steel

Due to several concerns, such as the possibility for chipping, machining stainless steel can be a complex process. Here are some suggestions that may help with machining this alloy:

Apply coolants or lubricants to the equipment Use large tools to help dissipate heat Maintain light cuts and constant feeds Use chip breakers to deflect debris Select a machine tool that reduces vibration Keep the cutting edge sharp at all times

Welding Stainless Steel

Most types of stainless steel can be welded, but the degree of efficiency depends on the grade. Here are some tips for welding each category of stainless steel:

Austenitic: most grades of the austenitic family, except for free-machining Grade 303, are well-suited for welding purposes. However, this group is susceptible to sensitization and inter-granular corrosion on thicker products. For projects that involve welding thick materials, it may be better to use low carbon content grades such as 304L or 316L. Some stabilized grades, such as Grade 347, may also be effective.

Martensitic: these grades are also good options for welding, but may be prone to cracking. To help reduce the likelihood of fractures, pre-heat and post-heat the material, or use supplementary austenitic filler rods.

Ferritic stainless steel: though relatively less suitable for welding, some stabilized ferritic grades, such as Grade 409, may be appropriate for certain projects. Issues such as sensitization, low ductility, and high grain growth may be overcome with the help of austenitic stainless steel fillers or by post-heating the welded material.

Duplex: this set of grades works well for low thermal expansion and is welding efficient. Some suitable welding grades such as Grade 2205, have higher nickel content to improve ductility, strength, and corrosion resistance.

Alloys Used Die Casting

As a fabrication process, die casting is notable for its capacity to manufacture parts with a high degree of uniformity, close design accuracy, and quality surface finishes. In many cases, die casting can reduce or eliminate the need for post-production machining, raising the cost-efficiency of the process and shortening fabrication time. While it may be difficult to die cast sturdier metals, such as certain grades of steel, there are many other types of alloys well-suited for die casting methods.

Die casting molds are usually constructed from hardened steel and they are often the most expensive component in a die casting machine. These molds can handle a range of different alloy families with varying results, but die casting is generally most effective on metals with low fusing temperatures. For this reason, the common die casting alloys fall into a handful of categories based on their composition and material properties.

Zinc Alloys

Zinc-based materials are relatively easy to die cast, and respond well to the die molding process. These materials are comprised of multiple metals in specific ratios. For example, a typical zinc-based die casting workpiece consists of 86 percent zinc, 4 to 7 percent copper, and 7 to 10 percent tin. Slightly higher proportions of tin make the workpiece more flexible, while increased copper levels improve rigidity. Zinc alloys have a melting point in the range of 700 to 800 degreees Fahrenheit.

Zinc alloys are often used in place of cast iron or brass, but tend to have lower tensile strength than their sturdier counterparts. Unless it is specially reinforced during the alloying process, zinc-based material cannot exceed approximately 17,000 pounds per square inch of force. As a result, die cast zinc products are generally not used in applications involving high mechanical loads. Zinc castings can also be corroded by alkaline substances or salt-water, and are often plated to preserve their luster despite atmospheric conditions.

Tin Alloys

Alloys composed with a significant amount of tin as a base metal are most often used in applications requiring corrosion resistance, such as those involving the food industry or internal and external bearings. While the proportion of metals in these alloys can vary widely, a typical tin alloy consists of 90 percent tin, 6 percent antimony, and 4 percent copper, which is added to strengthen the material’s durability. Tin alloy die castings generally weigh under ten pounds and rarely exceed 1/32 of an inch in thickness. They are valued for their resistance to alkaline, acids, and water, but feature a comparatively low tensile strength rating of below 8,000 pounds per square inch. Bronze and Brass Alloys Most bronze and brass materials can be die cast as effectively as zinc-based alloys, although small holes can only be drilled into the workpiece after casting, rather than during the casting process. Bronze and brass are commonly used to create washers, camshaft components, and decorative products (due to their distinctive coloring and potential for surface finishes). A typical brass alloy consists of 60 percent copper, 40 percent zinc, and 2 percent aluminum, but there are many variations on this mixture. Die casting bronze and brass is capable of yielding products with a durable surface and highly accurate interior specifications.

Some brasses have difficulty tolerating shrinkage from high temperature processes, but despite these challenges, most of these alloys can be used for products weighing up to fifteen pounds and with thicknesses at or under 1/32 of an inch. They are generally suitable for applications requiring tensile strength of less than 8000 pounds per square inch.

Aluminum Alloys

Die cast aluminum alloys are often found in automobile parts and gears, and have been used to create surgical instruments in the past. They are generally stronger and lighter than most zinc-based materials, but tend to be more expensive to create. Using aluminum alloys can reduce the need for finishing treatments, such as plating, and a common grade is composed of 92 percent aluminum mixed with 8 percent copper. Magnesium may be added to this alloy to improve its tensile strength from around 21,000 pounds per square inch to approximately 32,000 per square inch, while nickel can be included to increase rigidity and provide a higher surface finish. The melting point for an aluminum alloy is around 1150 degrees Fahrenheit.

Lead Alloys

Like tin alloys, lead-based materials tend to be used for their corrosion resistance and in applications requiring no more than 8000 pounds of tensile strength per square inch. Common applications include fire-safety equipment, bearings, and various decorative metal goods. They are relatively inexpensive for producing castings under 15 pounds, but lead alloys cannot be used for products that will be in contact with food. A typical lead alloy might be 90 percent lead and 10 percent antimony, with tin being a common addition as well. The melting point is usually around 600 degrees Fahrenheit, and product thickness rarely exceeds 1/32 of an inch.

For insight on the history of die casting procedures and the scientific principles underpinning them, please see Die-Casting, by Edmund Francis Lake and Chester L. Lucas.

Aluminium Extrusion in Construction

Aluminum extrusion has become an important feature in construction because of its cost benefits and structural integrity. Additionally, aluminum is prized for adding metal accents to glass surfaces. Because aluminum extrusion allows for complex shapes on long continuous pieces, it can be exploited for numerous different construction materials.

The Extrusion Process

Extrusion is a process of shaping different molten materials, like metals or plastic, by forcing them through shaped designs at high pressures. Because of the process’s flexibility, there are a number of methods for performing it, including hot or cold, and continuous or semi-continuous.

A really simple analogy for extrusion would be a pasta machine. The prepared dough is sent through a press, which emits long, continuous strands of spaghetti. Metal extrusion is very similar, except on much larger scale. A mostly automated process involves workers melting down a metal to its molten form, then transferring it to the extrusion machine. The extrusion machine then forces the molten metal, by way of either hydraulic or mechanical power, through a steel die at high pressure. If it’s a continuous extruder, the press will continue to force the metal in one long, continuous section until the piece is done. If it’s semi-continuous, the press will cut off the pieces one by one as the metal is forced through the die. The finished pieces are then transported further down the assembly line for cleaning and finishing.

Costs for extrusion are limited to die molding, materials and manpower. Because an extrusion press can be outfitted with different dies, a manufacturer investing in the press will see longterm use. Steel dies vary in price but can be expensive for more intricate, precision varieties. With aluminum extrusion, the customer is fortunate to be using a relatively inexpensive metal that also has desirable strength capabilities. Although not on the level of a case-hardened steel, aluminum’s structural integrity is quite robust while remaining light, which is why it sees use in aerospace and construction applications.

Extruded Aluminum in Construction

Extruded aluminum products are versatile, both in application and production. Manufacturing extruded aluminum can be done by either cold or hot processes, continuously or semi-continuously. Lightweight extruded aluminum paneling or guide rails are common for trailer, shed and furniture construction, but denser aluminum structures are becoming common.

Recent construction in Chicago has employed over a million tons of extruded aluminum parts. Architects of recent high profile projects going up in “The Loop,” the Second City’s famed business district, have spoken of consciously trying to fit their buildings into Chicago’s Art Deco style, while retaining a contemporary feel. An executive V.P. at Lohan Caprile Goettsch Architects said that extruded aluminum was a “perfect choice,” to maintain this classic feel, while also serving utilitarian ends. “The extruded profiles are thermally improved, so heat doesn’t transmit through the curtainwall system,” he said.

Extruded aluminum is not just limited to exterior design and function, either. Lighting fixtures, elevator shafts and stairwells all employ many different applications. While aluminum can’t make up the basic frame skeleton of a building, it accents and aids the structure in the interior. Integrated extruded aluminum design features in almost all areas of building construction, including structural mechanical, plumbing and others.

Additional bonuses to using extruded aluminum are the reusability and recyclability of the material. It is a product that is fairly easy to re-appropriate or to refashion into another use, or properly melt down and completely recycle. This makes it additionally desirable to environmentally-conscious architects and manufacturers.

References:

Aluminum Extrusion Showcase, “High-Rise building the Green Way is Transforming Chicago’s Skyline.”http://www.aec.org/exapps/greenbuildingdesign.html"