What are the signs of heavy metal poisoning. How does heavy metal toxicity occur. What are the most common treatments for metal poisoning. How can you prevent exposure to harmful metals.

Understanding Heavy Metal Poisoning: A Comprehensive Overview

Heavy metal poisoning is a serious condition that occurs when the body accumulates toxic levels of certain metals. While some heavy metals like iron and zinc are essential for our health in small amounts, excessive exposure to these or other metals can lead to severe health complications. This article delves into the intricacies of heavy metal poisoning, exploring its causes, symptoms, diagnosis, and treatment options.

Common Heavy Metals and Their Sources

Several heavy metals can cause poisoning when present in high concentrations. These include:

• Arsenic
• Lead
• Mercury
• Cadmium
• Copper
• Iron
• Zinc

These metals can be found in various sources, including:

• Contaminated water
• Industrial emissions
• Old paint
• Certain fish species
• Uncoated cookware
• Some herbal medicines

How does heavy metal exposure typically occur?

Exposure to heavy metals can happen through multiple routes:

1. Ingestion of contaminated food or water
2. Inhalation of metal-containing dust or fumes
3. Absorption through the skin
4. Occupational exposure in certain industries

For instance, workers in factories that use heavy metals may be at higher risk of exposure. Similarly, individuals living in older homes with lead-based paint can be exposed to lead dust during renovation activities.

Recognizing the Symptoms of Heavy Metal Poisoning

The symptoms of heavy metal poisoning can vary depending on the specific metal involved and the level of exposure. Generally, there are two types of poisoning: acute and chronic.

Acute Heavy Metal Poisoning

Acute poisoning occurs when an individual is exposed to a high dose of heavy metals in a short period. Symptoms may include:

• Confusion
• Numbness
• Nausea and vomiting
• Loss of consciousness
• Abdominal pain
• Diarrhea
• Dehydration
• Tingling sensations

Chronic Heavy Metal Poisoning

Chronic poisoning results from long-term exposure to lower doses of heavy metals. Symptoms may develop gradually and include:

• Persistent headaches
• Fatigue and weakness
• Joint and muscle pain
• Constipation
• Cognitive impairment
• Developmental delays in children

Diagnosing Heavy Metal Poisoning: Tests and Procedures

Diagnosing heavy metal poisoning requires a combination of clinical assessment and laboratory tests. Healthcare providers may use the following methods:

• Blood tests
• Urine analysis
• X-rays
• Complete blood count (CBC)
• Kidney and liver function tests
• Electrocardiogram (ECG)

Are heavy metal toxicity tests routine?

No, heavy metal toxicity tests are not routinely performed. Doctors typically order these tests only when there are clear symptoms and a history of potential exposure to heavy metals. If you suspect heavy metal poisoning, it’s crucial to consult a healthcare professional who can assess your symptoms and exposure risk before recommending appropriate tests.

Treatment Options for Heavy Metal Poisoning

The primary goal in treating heavy metal poisoning is to remove the source of exposure and eliminate the toxic metals from the body. Treatment approaches may include:

1. Supportive care: Managing symptoms and preventing further complications
2. Chelation therapy: Using medications that bind to metals and help the body excrete them
3. Gastric lavage: In cases of recent ingestion, the stomach may be pumped to remove the toxins
4. Dietary changes: Adjusting diet to reduce further exposure and support the body’s natural detoxification processes

How effective is chelation therapy for heavy metal poisoning?

Chelation therapy can be an effective treatment for certain types of heavy metal poisoning, particularly in cases of lead and mercury toxicity. However, it’s not without risks and is typically reserved for severe cases with confirmed high levels of heavy metals in the body. The effectiveness and safety of chelation therapy can vary depending on the specific metal involved and the individual’s overall health status.

Preventing Heavy Metal Exposure: Practical Steps

Prevention is key when it comes to heavy metal poisoning. Here are some practical steps to reduce your risk of exposure:

• Test your home’s water supply for contaminants
• Use water filters certified to remove specific heavy metals
• Be cautious when consuming fish, especially large predatory species
• Avoid using uncoated cookware that may leach metals into food
• Take proper safety precautions when working with potentially toxic materials
• Keep your home well-ventilated, especially during renovation projects
• Be aware of potential sources of heavy metals in your environment and workplace

Can dietary choices help prevent heavy metal accumulation?

While a balanced diet cannot completely prevent heavy metal exposure, certain foods may help support the body’s natural detoxification processes. Foods rich in antioxidants, fiber, and sulfur compounds may aid in the elimination of heavy metals. These include:

• Leafy green vegetables
• Garlic and onions
• Cilantro
• Berries
• Cruciferous vegetables like broccoli and cauliflower

However, it’s important to note that diet alone is not a substitute for proper medical treatment in cases of heavy metal poisoning.

Debunking Myths: Unproven Tests and Treatments

While heavy metal poisoning is a serious concern, it’s important to be aware of potentially misleading information and unproven treatments. Some common myths and misconceptions include:

Are hair analysis tests reliable for detecting heavy metal poisoning?

Hair analysis tests are often marketed as a way to detect heavy metal poisoning, but their reliability is questionable. While hair can contain traces of metals, the levels found in hair don’t necessarily correlate with the levels in the body or indicate poisoning. Most medical experts do not recommend hair analysis as a diagnostic tool for heavy metal toxicity.

Do detox foot baths remove heavy metals from the body?

Despite claims made by some alternative health practitioners, there is no scientific evidence to support the effectiveness of detox foot baths in removing heavy metals from the body. The color changes often observed in the water during these treatments are typically due to the electrolysis of the water itself, not the removal of toxins from the body.

Can chelation therapy be used for general detoxification?

Chelation therapy is a medical treatment specifically designed for certain cases of heavy metal poisoning. It is not recommended for general detoxification or as a preventive measure. Unnecessary chelation therapy can be harmful, potentially causing kidney damage, depletion of essential minerals, and other side effects.

The Role of Environmental Policies in Reducing Heavy Metal Exposure

Environmental policies play a crucial role in protecting public health from heavy metal exposure. These policies aim to:

• Regulate industrial emissions
• Set standards for drinking water quality
• Limit the use of heavy metals in consumer products
• Promote safe waste disposal practices
• Enforce occupational safety standards in industries dealing with heavy metals

How effective have environmental regulations been in reducing heavy metal exposure?

Environmental regulations have significantly reduced heavy metal exposure in many developed countries. For example, the ban on leaded gasoline has led to a dramatic decrease in blood lead levels in the general population. Similarly, stricter regulations on mercury emissions from coal-fired power plants have helped reduce mercury levels in fish and other wildlife.

However, challenges remain, particularly in developing countries where regulations may be less stringent or poorly enforced. Global efforts to address heavy metal pollution continue, with international agreements like the Minamata Convention on Mercury aiming to protect human health and the environment from anthropogenic emissions and releases of mercury and mercury compounds.

Emerging Research and Future Directions in Heavy Metal Toxicology

The field of heavy metal toxicology is constantly evolving, with new research shedding light on the complex interactions between heavy metals and human health. Some areas of current interest include:

• The role of genetic factors in susceptibility to heavy metal toxicity
• The potential link between heavy metal exposure and neurodegenerative diseases
• Development of more sensitive and specific biomarkers for heavy metal exposure
• Investigation of the cumulative effects of low-level exposure to multiple heavy metals
• Exploration of novel chelation agents with improved safety and efficacy profiles

How might advancements in toxicology impact future treatment approaches?

As our understanding of heavy metal toxicity grows, it’s likely that treatment approaches will become more personalized and targeted. For instance, genetic testing might help identify individuals who are more susceptible to certain heavy metals, allowing for tailored prevention strategies. Additionally, advancements in nanotechnology and drug delivery systems could lead to more effective and less invasive treatments for heavy metal poisoning.

Furthermore, improved understanding of the mechanisms of heavy metal toxicity at the cellular and molecular levels may pave the way for new therapeutic strategies. These could include treatments that enhance the body’s natural detoxification pathways or protect against the oxidative stress caused by heavy metal exposure.

The Global Perspective: Heavy Metal Pollution as an International Concern

Heavy metal pollution is not confined by national borders, making it a global environmental and health issue. Some key aspects of this global perspective include:

• Transboundary pollution through air and water
• The impact of global trade on heavy metal exposure
• Disparities in exposure between developed and developing countries
• The role of international organizations in addressing heavy metal pollution

How do international efforts address heavy metal pollution?

Several international initiatives and agreements aim to address heavy metal pollution on a global scale:

1. The Stockholm Convention on Persistent Organic Pollutants, which includes provisions for certain heavy metals
2. The Basel Convention, which regulates the transboundary movement of hazardous wastes, including those containing heavy metals
3. The Strategic Approach to International Chemicals Management (SAICM), which provides a policy framework to promote chemical safety around the world
4. The Global Mercury Partnership, led by the United Nations Environment Programme, which works to protect human health and the environment from the releases of mercury and its compounds

These international efforts focus on various aspects of heavy metal pollution, including reducing emissions, improving waste management, and promoting safer alternatives to heavy metal-containing products.

Education and Awareness: Key Components in Preventing Heavy Metal Poisoning

Raising public awareness about heavy metal poisoning is crucial for prevention and early detection. Educational efforts should focus on:

• Identifying common sources of heavy metal exposure in daily life
• Understanding the health risks associated with different heavy metals
• Recognizing the symptoms of heavy metal poisoning
• Learning about proper safety measures when working with potentially toxic materials
• Understanding the importance of proper disposal of heavy metal-containing products

How can individuals contribute to reducing heavy metal pollution?

While large-scale efforts are necessary to address heavy metal pollution, individuals can also play a role in reducing exposure and environmental contamination:

1. Properly recycle electronic waste, which often contains heavy metals
2. Choose alternatives to products known to contain heavy metals when possible
3. Support local and national initiatives aimed at reducing heavy metal pollution
4. Stay informed about local water quality and take appropriate precautions if contamination is detected
5. Advocate for stronger environmental regulations and enforcement

By combining individual actions with broader policy initiatives and continued scientific research, we can work towards minimizing the health risks associated with heavy metal exposure and creating a safer environment for current and future generations.

Heavy Metal Poisoning & Toxicity: Symptoms, Causes, and Treatment

Written by R. Morgan Griffin

• What Is Heavy Metal Poisoning?
• Heavy Metal Poisoning Causes and Risk Factors
• Heavy Metal Poisoning Symptoms
• Heavy Metal Poisoning Diagnosis
• Heavy Metal Poisoning Treatments and Home Care
• Unproven Tests and Treatments for Heavy Metal Poisoning
• Heavy Metal Poisoning Prevention
• More

Heavy metal poisoning can happen when you’re exposed to a lot of certain types of metals. It makes you sick and affects the way your body works.

Heavy metals, like arsenic, lead, mercury, and others, are all around us. They’re in the ground we walk on, in the water we drink, and in the products we use every day. But high levels of most heavy metals can cause health problems.

The poisoning can happen if you eat or drink something tainted with heavy metals or if you breathe in contaminated dust or fumes.

True heavy metal poisoning is rare in the United States. And experts say you should be careful about unproven heavy metal tests or “detox” treatments you find online. They may waste your money, and some could be dangerous.

There are many heavy metals, including:

• Arsenic
• Cadmium
• Copper
• Iron
• Lead
• Mercury
• Zinc

Not all of these metals are bad for you. We need small amounts of some of them, such as copper and iron, to keep our bodies healthy.

You might get heavy metal poisoning if you:

• Work in a factory that uses heavy metals
• Breathe in old lead paint dust when you fix up your home
• Eat fish caught in an area with high levels of mercury
• Use herbal medicines that have heavy metals in them
• Use dinnerware that hasn’t been coated well enough to prevent heavy metals from contaminating food
• Drink water contaminated with heavy metal.

The signs can vary, depending on the metal and the amount.

Acute poisoning. This happens if you get a high dose at one time, like in a chemical accident in a factory or after a child swallows a toy made with lead. Symptoms usually come on quickly, and you may:

• Feel confused
• Go numb
• Feel sick and throw up
• Pass out

You may also have:

• Abdominal pain
• Diarrhea
• Dehydration
• Tingling
• Anemia
• Kidney damage
• Liver damage
• Lung irritation
• Fluid in your lungs
• Brain problems or memory loss
• Horizontal lines on your nails
• Behavioral changes
• Weak or malformed bones
• Miscarriages or premature labor

Acute poisoning is an emergency. Call your doctor or local poison control center right away. The national Poison Help Line is 800-222-1222.

Chronic poisoning. You get this after contact with a low dose over a long time. As the metal builds up in your body, you can get sick. Symptoms come on slowly and can include:

• Headache
• Weakness and tiredness
• Achy joints and muscles
• Constipation

Drinking water with lead in it can lead to cognitive problems and slower development in kids. Infants who drink formula mixed with tap water are at especially high risk if their drinking water is contaminated.

Lead has been banned from plumbing for years, but it still gets into the water supply from old lines. Some water filters will remove it from your water, but if you’re concerned about the level of lead in your drinking supply, you can request a water test.

Different tests can check for different types of heavy metals. Some might test your blood or pee. Others might require an X-ray. These tests can help your doctor decide if you have heavy metal poisoning, how severe it is, and which heavy metals are involved. They include:

• CBC (complete blood count)
• Kidney function tests
• Urine analysis for proteins
• Liver function tests
• Imaging tests (abdominal radiographs)
• Electrocardiogram

Your doctor will also ask you about your job, hobbies, diet, and anything else that could have put you in contact with dangerous substances.

Tests for heavy metals aren’t routine. Your doctor would test you only if you show symptoms and there is a history of exposure or a good reason to suspect they are related to heavy metals.

The main step is to stay away from whatever made you sick so you don’t make the problem worse. Your doctor can help you figure out how to protect yourself.

Sometimes you might need to have your stomach pumped to get the metals out.

If your poisoning is serious, one treatment option is chelation. You get drugs, usually through an IV needle, that go into your blood and “stick” to the heavy metals in your body. They then get flushed out with your pee.

Chelation can be an important part of treatment. But the therapy can be dangerous, and it doesn’t work with all heavy metals. So doctors use it only if you have high levels of the metal and clear symptoms of poisoning.

Experts say that heavy metal poisoning is rare. But lots of websites claim it’s common and blame it, without proof, for all sorts of health problems. Many businesses sell unreliable tests and expensive or even dangerous treatments.

Hair analysis or chelation challenge tests (“provoked urine” tests): They’re inaccurate. They can’t tell you if you’re sick or need treatment.

Over-the-counter chelation treatments: These are not approved by the FDA, may not be safe, and there’s no evidence that they work.

If you think you have heavy metal poisoning, don’t try to diagnose it or treat it on your own. See your doctor instead.

If you’re worried about heavy metal poisoning, your doctor can give you personalized advice.

General tips include:

• If you work with heavy metals, always wear a mask or other safety equipment.
• Check local fish advisories to make sure the fish you eat is safe.
• If you live in a home built before 1978, hire an expert to test it for lead paint and, if found, to do lead abatement.
• Check labels on products for heavy metals.

Top Picks

Heavy Metal Poisoning Symptoms | Signs of Heavy Metal Poisoning

Medically reviewed by Neka Miller, PhD on January 21, 2021. To give you technically accurate, evidence-based information, content published on the Everlywell blog is reviewed by credentialed professionals with expertise in medical and bioscience fields.

Table of contents

• What is heavy metal poisoning?
• Heavy metal toxicity symptoms
• Diagnosing and treating heavy metal poisoning
• Related content

Excessive exposure to certain chemical elements can be dangerous. Heavy metals are one class of chemical elements that can contribute to some severe and sometimes life-threatening issues. Knowing the symptoms to look out for may help you protect your health against the effects of heavy metal toxins. Continue reading to learn more about the signs and symptoms of heavy metal poisoning, how it’s diagnosed and treated, and more.

Related: Effects of Heavy Metals on the Body

What is heavy metal poisoning?

Heavy metals are a category of elements in the periodic table. The term refers to naturally-occurring metallic elements that are especially dense (in other words, they are “heavy for their size” compared to many other elements). Examples of heavy metals include copper, platinum, mercury, and lead.

Heavy metals have a wide range of applications in various industries, including medicine, agriculture, and even food. In fact, your body naturally contains heavy metals that are necessary for basic bodily functions, including zinc, copper, and iron.

Heavy metal poisoning can happen when you absorb too much of any particular heavy metal toxin. This can occur with potentially any metal if it is present in high enough quantities. However, the four most common heavy metals that can get absorbed in toxic amounts are:

• Arsenic
• Cadmium
• Lead
• Mercury

Under normal circumstances, it can be difficult to absorb significantly high concentrations of those four heavy metals, but they can be present in food, pollution, and more. Most often, heavy metal poisoning occurs over a long period of time, like working in an industry where you are consistently exposed to a heavy metal toxin without the proper protective gear.

Heavy metal toxicity symptoms

In the United States, heavy metal poisoning is relatively rare. Yet as rare as it is, it can help to know the possible signs and symptoms in case you or someone you know is affected by it. Heavy metal poisoning symptoms can vary based on the metal, but some general symptoms that overlap through most instances of excessive exposure to heavy metals include:

• Nausea and vomiting
• Diarrhea
• Abdominal pain
• Tingling sensation in the hands and feet
• Shortness of breath
• Sudden chills
• Weakness and fatigue

Children may experience bone deformities or generally weak bones. Heavy metal poisoning during pregnancy can potentially contribute to premature births or miscarriages.

Along with the above, different metals can also exhibit their own specific symptoms, as described below.

Arsenic poisoning symptoms

Arsenic is commonly used in chemical pesticides and certain industrial applications. Overexposure to arsenic compounds can lead to drowsiness, headaches, confusion, and seizures. It can also contribute to neurological symptoms, including significant brain damage, nerve disease in your extremities, and a breakdown of the fatty layer covering nerve fibers, known as the myelin sheath.

Arsenic poisoning can also affect the skin, resulting in a collection of arsenic in the soft layers just below the skin, known as edema. Arsenic accumulation can also cause white bands extending across the fingernails. Some people may experience bad breath odors that smell like garlic.

With chronic arsenic exposure—usually a result of working in environments where the heavy metal toxin is common—people may experience a significant weakening of muscles and muscle aches, along with chills and a fever. They may also exhibit hardened patches of skin on their palms and feet, known as hyperkeratosis, as well as unusual darkening or reddening of the skin and scale-like inflammation. These symptoms can occur between two and eight weeks after initial exposure.

Inorganic arsenic, which can be found in soil, sediment, and groundwater, can accumulate in the liver, kidneys, lungs, and digestive tract. While the symptoms may be similar to the above, inorganic arsenic operates slightly differently, leaving a residue within your organs, along with common tissues like skin and hair. Acute inorganic arsenic poisoning can cause gastrointestinal issues (diarrhea, vomiting, and nausea), muscle spasms, severe burning in the throat and mouth, and abdominal pain.

Cadmium poisoning symptoms

Cadmium is found in batteries, vapor lamps, electroplating, and some soldering products. Symptoms of cadmium poisoning can occur as soon as two to four hours following exposure. Accumulation of cadmium can lead to muscle pain and lung issues, including:

• Emphysema (a progressive loss of lung function)
• A buildup of fluid in the lungs
• Breathlessness

Cadmium poisoning can also lead to kidney damage that is characterized by:

• High levels of protein in the urine
• Changes to liver function
• Softening of bones

Lead poisoning symptoms

Lead is most commonly found in lead-based paint items, which can include toys. It may otherwise be found in art supplies and contaminated dust. Although lead gets stored in the bones, the toxic metal can have severe effects on every organ as well as mental functions. Symptoms can also vary based on your age and the severity of exposure.

In children, lead poisoning symptoms can develop over three to six weeks. Heavy lead exposure can cause kids to suddenly become sluggish, less playful, clumsier, or more irritable. It may also contribute to:

• A lack of appetite
• Constipation
• Slurred speech
• Fluctuations in kidney function
• Low levels of iron in the blood, which can appear as unusually pale skin

Some children may experience significant behavioral or learning problems, including sudden deficiencies in cognitive function and coordination.

In adults, lead poisoning can lead to:

• Low iron levels
• High blood pressure
• Damage to reproductive organs
• Insomnia and general sleep issues
• Reduced muscle strength
• Increased irritability
• Hallucinations
• Mental and behavioral changes (such as depression, anxiety, or increased hostility)

Mercury poisoning symptoms

Mercury is a naturally occurring metal found in soil and water. This means that small amounts of mercury eventually finds its way into certain food products. While that amount is usually not enough to cause alarm, some foods contain more mercury than others.

Mercury poisoning is most commonly attributed to consuming too much methylmercury, an organic form of mercury found in seafood. Eating high amounts of seafood over an extended period of time may contribute to mercury poisoning symptoms.

Mercury poisoning usually occurs over a long period of time. It can result in:

• Increased irritability
• Memory issues
• Anxiety
• Depression
• Tremors
• Shyness
• Numbness

In adults, mercury poisoning may also contribute to:

• Sudden speech and hearing difficulties
• Muscle weakness
• A lack of coordination
• Loss of feeling in the face and hands
• Sudden, significant vision changes
• Trouble with walking and mobility

High levels of mercury exposure can also have severe effects on early childhood development. Young children and infants who have been exposed to high levels of mercury may experience delays in fine motor skills, cognition, spatial awareness, and language development later on in life.

Diagnosing and treating heavy metal poisoning

Healthcare providers perform a variety of diagnostic tests to determine if you are suffering from any form of heavy metal poisoning, and whether a heavy metal detox is necessary. Common tests to diagnose heavy metal toxicity and determine its severity include:

• Complete blood count tests
• Kidney function tests
• Urinalysis
• Imaging tests
• Electrocardiogram
• Liver function tests

For milder cases of heavy metal toxicity, eliminating exposure is usually enough to treat symptoms and flush the accumulated metals from the body. In severe cases of chronic exposure, healthcare providers may prescribe chelation therapy. This involves the use of drugs that bind to heavy metals and speed up their elimination from the body.

How do you get mercury poisoning?

7 common mercury poisoning symptoms

Cadmium poisoning: causes and symptoms

References

1. Heavy Metal Blood Test. MedlinePlus. URL. Accessed January 21, 2021.

2. Heavy Metals. StatPearls [Internet]. URL. Accessed January 21, 2021.

3. Heavy Metal Poisoning. National Organization for Rare Disorders. URL. Accessed January 21, 2021.

4. How People are Exposed to Mercury. United States Environmental Protection Agency. URL. Accessed January 21, 2021.

5. Choose Fish and Shellfish Wisely. United States Environmental Protection Agency. URL. Accessed January 21, 2021.

6. Heavy metal poisoning. Genetic and Rare Diseases Information Center. URL. Accessed January 21, 2021.

How to Design a Metal Case

Fundamentals of Designing Metal Cases for Electronics and Instrumentation

Many Protocase users are true experts in their field, but do not always have knowledge of the design or manufacture of metal products. But developing an optimal design for a case that reflects your idea and requirements is a serious task. So for the last decade we have been creating an information resource containing our knowledge of sheet metal and the fundamentals of sheet metal case design. We hope that they will help you get started and save time by avoiding multiple rework in the future.

This article highlights the five key elements of design: metal selection, metal bending, clamping fasteners, welding, and finishing.

Choice of metal

When designing a case, the material type and thickness must first be selected. Among the main materials used for REA cases are aluminum, stainless steel, carbon steel (galvanized and cold rolled) and copper. Below is a description of the characteristics of each of these metals.

Aluminum

is a lightweight, corrosion resistant metal, excellent for housings and sheet metal applications. Can be powder coated or left uncoated, with or without sanding. If necessary, electrical contact aluminum chromate. Aluminum can also be anodized, a process that will create a hard and durable oxide coating.

In some cases, aluminum may have a stiffness factor lower than steel; it is likely that a thicker case may be required for special cases.

Most common alloys:

1. Aluminum 5052 – ideal for housings and sheet metal parts, as it can bend to a small radius without breaking. It is easy to weld and process.

2. 6061 Aluminum – Easily machined, but more prone to fracture when bent to small radii.

Cold rolled steel

– like aluminum, it is widely used in the manufacture of cases. It has a good combination of price and strength, as well as durability, provided that the product is powder coated and used indoors. However, by itself, such steel is not resistant to corrosion; if this property is important, aluminum, stainless steel or galvanized steel should be used.

Stainless steel

– has the strength and toughness of cold rolled steel, but is resistant to corrosion due to the content of chromium and nickel. Supplied powder coated, unpainted or sanded for a brushed look.

Zinc plated steel

is mild steel with a protective galvanized zinc coating (to prevent flaking). This coating prevents the formation of corrosion when using the product in wet areas. Although corrosion resistance is not as high as that of aluminum and stainless steel.

Copper

is a soft, flexible and malleable metal with a high degree of thermal and electrical conductivity. Typically used for tires, but can also be used for hulls. When working with this metal, be careful when tightening fasteners, as soft copper will warp under excessive force. The best solution would be to use self-clamping fasteners.

Custom openings

Metal enclosures often have cutouts in a variety of shapes and sizes. As a rule, these are holes for connectors, displays, switches, etc. It can also be cutouts with custom shapes and purposes, including logos, brands or product names, as well as custom vents that combine aesthetic form and function.

Metal bending and bending radius

Body and sheet products metal is bent by a stamping press or a bending machine. As a rule, metal cannot be bent to a perfect right angle and most often there is a small radius, as seen in the figure below.

The use of different tools and techniques allows different bending angles to be achieved. When designing the hull, you control this parameter by setting bend radius is the radius of the inside surface of the bend (the outside radius is the sum of the inside radius and metal thickness).

Key Bend Angle Factors:

Functional Considerations : You don’t know the size of the flat part for clips, components, or cutouts until you have a clear bend radius.

Aesthetic considerations : For example, retro designs often require a larger radius for a more rounded appearance.

Keep these considerations in mind when choosing a bend radius.

Pay special attention to the intersection of the two fold lines (ie corner) of the housing. In particular, excess material must be removed to prevent obstruction between corners; this is called “corner release” (“corner cutting” in CAD systems).

As a general rule, cutouts must be a certain minimum distance from bend corners to avoid flaring or stretching the hole. This distance is determined by the type of material, its thickness and the tool used for bending, as well as the value of the radius. Whatever minimum bend you choose, make sure the holes are at least the same distance from the bend. For example, when using 14 gauge stainless steel and aiming for a minimum .275″ flex, cutouts should be no closer than .275″ to the flex.

If a hole needs to be placed close to a bend, the part must be discussed with production. It is possible to cut a notch in the bend area to maintain the desired shape of the hole:

Self-locking fasteners

Self-locking fasteners are threaded nuts, pins and other similar products that are pressed into sheet metal to create one-piece attachment points. Nuts can be used for screws (a more reliable solution than tapping directly into metal), racks for mounting printed circuit boards on them, and pins for attaching connectors. PEM (Pennsylvania Engineering and Manufacturing Standoffs) self-locking fasteners are extremely handy and help solve a wide variety of component fastening tasks.

Below is another example of the use of self-clamping fasteners:

Welding

Welding is used to solve various complex problems, for example, when creating complex parts (welding different parts into a single product), sealing joints or strengthening the body.

Spot welding

is a fast, efficient and inexpensive method of permanently joining two sheet metal parts at one or more points. Unlike the use of threaded connections, spot welding leaves a small mark. There are some restrictions in the application of this welding method, associated with the geometry of the welding equipment (see figure below). Spot welding is applicable to all kinds of cold rolled steel, stainless steel and galvanized steel.

Maximum weld thickness: 15″ (375mm)
Maximum height: 5″ (125mm)

Seam welding

– Suitable for permanent joining of two or more sheet metal parts with a seamless effect. We use the Cold Metal Transfer (CMT) method, similar at first glance to consumable electrode arc welding in inert gas (MIG). However, in MIG welding, the filler metal is deposited at extremely high temperatures. In CMT welding, the welding wire is heated to melt the tip and the transfer occurs through physical contact. When using CMT welding, heat generation is only 1/10 of that of MIG welding, which prevents metal distortion, even for thin products. Most often, excess metal is subsequently removed by grinding. The resulting junctions provide protection from external weather factors and reduce electromagnetic interference, as well as give the product a seamless look.

Tack welding

– similar to seam welding, but on separate parts of the product:

Finishing

Powder coating

– electrostatic application of dry thermoplastic powder, followed by high temperature curing in an oven. It has a wide selection of colors (http://ral.ru/classic_colours) and allows you to achieve various effects on the surface – gloss or texture. Powder coating is the industry standard for cost-effectiveness, high quality and durability. An undoubted advantage is also a wide choice of different textures, for example, rough coatings perfectly hide fingerprints on the case and are perfectly applied.

When powder spraying, the paint lays an additional layer on the body. The dimensions in the drawings indicate only the dimensions of the metal, without coating. It is recommended to add an additional 1-2 mm on each side for cutouts (for example, if a piece with dimensions of 25 mm is inserted into the cut hole, the hole size should be from 25 to 26 mm). Otherwise, the holes may be too small and the part will not fit in them.

Digital printing and screen printing

add a professional product feel to your design. Both of these techniques allow you to clearly label connectors, inputs, switches, and more. Digital printing also excels at imprinting images such as company logos.

Digitally printed and silk screened on flat panels, parts and assembled enclosures.

Although digital printing is the de facto standard for many designers, both techniques have their own advantages that you should consider when choosing the method that works best for you.

Chemical Conversion Coating

– Often referred to as chemical film or chromate. During chromating, a corrosion-resistant and durable coating (similar to stainless steel) with stable electrical conductivity is created on the metal surface.

Anodizing

is an electrochemical process used to prepare the surface of non-ferritic materials, primarily aluminium, to reduce corrosion and increase strength. The anodized surface becomes part of the aluminum so it does not peel, chip or peel. Under normal operating conditions, it does not wear out.

Tin Plating

– used to apply a layer of pure tin to a copper surface. Tin plating is applied to enhance corrosion resistance, better electrical conductivity and solderability.

Bare Metallic Coating

– Available in three basic finishes for aluminum and stainless steel:

No Coating – The part is sanded without additional coating, therefore small scratches or marks may be visible on the surface. Such details are economical, but not applicable to the visible parts of the product.

Graining – the part is ground and brushed.

Finisher – smoothes the surface with an abrasive material (visually resembles frosted glass).

Tolerances

Manufacturing tolerances are an important part of housing design. Sources of error are positioning errors and vibrations when cutting holes, deviations associated with the structure of the metal and imperfect simulation of stretching that occurs during bending. It is also important to remember that the dimensions are provided for bare metal without taking into account the coating – for powder coating, from 0. 07 to 0.1 mm are added on top.

Finished product

This is a translation of the original article https://www.protocase.com/blog/2017/02/16/electronic-enclosure-design-101/ we’ll try to help.

4 main types of metal for housings – differences and features

Sheet metal housings have common features that distinguish them from plastic housings or milled metal housings .

Contents of the article

• Metal vs plastic.
• Sheet vs cutter.
• Cold rolled black steel and steel bodies.
  • Steel and corrosion.
  • Steel weight.
• Zinc-plated and bodies made from it.
• Stainless steel and stainless steel cases.
• Aluminum and enclosures made from it.
• Housings and parts made of other metals?

Equipment case materials: metal vs plastic

Metal is stronger than plastic , metal case better protects its “stuffing” and lasts longer than . Plus, metal is special aesthetics .

Of course, the 80s are not in the yard for a long time, and the plastic case can also look decent and even beautiful for a long time. But pay attention – manufacturers, for example, top-end smartphones , in their fierce competition with each other, for a long time mainly switched to metal cases . This is not an accident. And the same pattern works for housings of more serious devices .

Equipment case materials: sheet vs cutter

As for the differences from milled metal cases, the main advantage of sheet metal cases over them is usually, of course, cost.

• By milling the case, is created from bulk blank – a metal blank from which everything superfluous is cut out. The problem is that this “superfluous” turns out to be a lot . Of course, the cut and sheared metal does not disappear anywhere, it is sent for remelting, reimbursing part of the money invested in the purchase of the material – but the price of such metal is much lower than for the blanks that went into work. And the difference in price, of course, is included in the cost of the case for the customer .
• When milling , metal is cut with metal . And metal consumables of machine tools are actively worn out. Of course, the cost of their wear and tear is also included in the price , which the customer will eventually pay for milled cases.

It is not possible to move from cutter to sheet everywhere – because not every shape can be repeated in sheet . round 3D parts with spigots will continue to be used by milling or casting. But you need to understand that many cases that are now manufactured in Russia by milling, in fact, could have been converted to sheet a long time ago. And customers of such buildings would get stunning benefit.

Let me give you an example – one of the customers of contacted us with a request to produce a milled body. We are not engaged in milling – but one glance of our designer at the body sample was enough to understand that with a couple of changes we can produce from a sheet with a body similar in function to . We proposed to work out this moment. The customer agreed.

As a result, the same body, converted into sheet metal and made in our production, had the cost price for the customer is 5 (five!) times less than the one that was produced for him by milling.

Of course, in order to find such solutions where no one could find them for years, the designer must be experienced and charged with some share of the sacred design madness . But we have such constructors. Contact if anything.

But we digress.

So, there is sheet metal, and it is different from milled metal – and both of them together are different from plastic. But. Sheet metal sheet metal strife .

There are 4 main and main types of sheet metal, which are used in the construction of instrument cases. And if you want your case to be perfect for your tasks and not make a hole in your budget – you need to understand the differences and choose the right metal.

Black cold rolled steel and cases made of it

Steel – the most popular type of sheet metal for instrument cases . First of all, of course, it plays here that among the suitable types of metal sheets, steel sheets are simply the cheapest. But at the same time, their strength and quality are at a decent level, there are no problems with this.

What are the problems then? Why isn’t steel, with its proper quality and reasonable prices, the only material used for sheet metal housings?

Steel and corrosion

First, issue corrosion. For the other three main types of sheet metal for housings, this issue is more or less closed. And steel without special protection rusts and becomes unusable easily and quickly .

Special protection – what is this special protection?

First coat of resin powder paint over metal. With a high-quality and undamaged painting, the steel will not corrode, as simply will not directly contact the external environment . Well, plus – powder coating is just beautiful.

However, the catch is that not all areas allow the use of painted metal. For example, many medical devices are required by regulation to remain unpainted , so as not to interfere with sterilization. Under such conditions, black steel is not applicable, we must look for other options.

Weight of steel

Next moment black steel remains is not the lightest material in terms of weight . There are cases when this is not critical, and even useful to some extent. For example, if you are making a case for an outdoor payment terminal , let it be rather heavy. Yes, of course, in a collision with vandals, he can still suffer . But let them suffer too .

However, this works, of course, is far from being everywhere . And many devices – for example, actively portable and some server ones – customers prefer to see in lighter housings .

However, cold rolled black steel continues to be the most popular material for sheet metal housings. By default, it is worth starting to think about it, if nothing requires the opposite.

Galvanized and galvanized housings

But for corrosion protection, steel can not only be painted. You can galvanize it in a special bath with a thin layer of zinc – and voila, the resulting material will be resistant to corrosion.

You can first do everything you need with the parts – cut, bend, weld – and then galvanize the result. Or you can initially work with galvanization – but here the difficulty is not to scratch the galvanizing layer anywhere during the production of .

Why is it important not to scratch the zinc layer? And here lies the big problem of galvanizing and its main drawback over full-fledged stainless steel.

The fact is that if the integrity of the outer zinc layer is broken, exposed steel begins to rust – and begins with furious force and speed . At the same time, the zinc layer cannot be called very stable – it can go through a deep scratch, it can be eaten by friction.

This is how the scope of galvanized housings and parts is outlined. They are used in cases where, on the one hand, it is impossible or simply undesirable to paint – and on the other hand, the surface of the metal will not be subjected to aggressive mechanical stress . For example, inner trays and x-ray brackets are galvanized with a bang.

And in other cases, when you need to protect yourself from corrosion, and not paint, and not be afraid for the safety of the outer layer – stainless steel is used.

Stainless steel and stainless steel cases

Stainless steel does not rust . Dot. It does not rust, if you put it in water, saw it in half – it will not rust on the cut. Unlike galvanizing.

It would be possible to refuse galvanizing altogether and use stainless steel in all cases – but stainless steel costs significantly more than . Therefore, if these additional costs are justified, it is not a question. And if you can get by with galvanizing, it will be more profitable to do so.

Stainless steel is more expensive in itself when purchased from suppliers, and in addition it requires when processing more expensive operations .

For example, for perfect laser cut quality, stainless steel is better than cut in shielding gas – at least nitrogen. The fact is that when heated to the cutting temperature, stainless steel still begins to react with oxygen, generating oxides that make the cut dirty. In order to exclude this reaction, it is necessary to remove oxygen from the cutting zone, with which the hot metal could react – that is, literally squeeze it out of there, replacing it with a jet of compressed nitrogen.

That is, firstly, you need compressed gas cylinders , and secondly, you need has more power than , because black steel, for example, is cut so quickly and easily by a laser precisely because it is not prevented from reacting with oxygen or even pure oxygen is supplied to the cutting zone. The oxidation reaction is exothermic, often by itself giving even more heat to melt the metal than a laser beam.

For high-quality welding of stainless steel, a shielding gas is also needed – usually argon, a truly inert gas with which the metal being welded is not able to react in any way .

Aluminum and housings made of it

Aluminum, like stainless steel, can be left unpainted or coated – it will not corrode . And to make its unpainted surface beautiful, it is polished .

At the same time, aluminum housings and parts compare favorably with steel due to their weight. For all devices whose designer wants to reduce their weight, it makes sense to consider the use of aluminum cases.

But of course aluminum will also be is more expensive than black steel, so it should be chosen when the increase in cost is really justified and pays off.

Housings and parts made of other metals?

Yes, of course – this is not a complete list of metals from which we can make a case for you. Just these materials are the most popular , most often you have to work with them, you can say a lot about them.

However, in rare cases it is possible to produce cases and parts from copper, brass, titanium, etc. . Any question can be discussed.

Do you need a housing? Contact us, let’s discuss the specifics of – the exact terms and cost of manufacturing products exactly according to your requirements.