• A PLACE FOR - INSPIRATION AND CHAT

    A PLACE FOR

    INSPIRATION AND CHAT

Surgical Metals

Posted December 12th 2017

The most commonly used metals in surgery are surgical stainless steel and titanium. Surgical stainless steel is a term used to label particular grades of stainless steel that are commonly used in biomedical appliances. The most common forms are austenitic 316 stainless steel and martensitic 440 and 420 stainless steels and whilst there is no certain definition of what constitutes surgical stainless steel, manufacturers generally recognise this to be any grade of corrosion resistant steel.

316 stainless steel is an alloy of chromium, nickel and molybdenum that is highly resistance to corrosion and relatively strong. 316 stainless steel can be cheaper to produce than the commonly used titanium alloy, Ti6AI4V, and as such is commonly used in the production of biomedical implants. Its drawback, however, is the nickel content which can induce a reaction with the immune system and cause complications. For any implants which may be subject to pressure once in place, such as body piercings, bone fixation screws and prostheses, austenitic steel is more commonly used.

Titanium has been commonly used for biomedical purposes since the 1950s, after already having been used in dentistry prior to this. It is commonly used to make prosthetics and can be used as the material for biomedical implants all over the body from false eye implants and spinal fusion cages, to pacemakers and hip replacements. In addition to thus, several surgical instruments are coated with titanium nitrade, an extremely hard ceramic material that hardens and protects surfaces. Titanium is commonly considered to be the most biocompatible metal due to its high level of corrosion resistance and high fatigue limit. A protective oxide film forms naturally in the presence of oxygen, which protects it from bodily fluids and prevents reactions between the metal and hosting environment.

Although both materials are useful, there are several differences between them that make them suitable for different things. Titanium is stronger and more lightweight than stainless steel, and less rigid which can limit the amount of stress placed on bones. It also lasts longer and generally has superior strength to stainless steel, although stainless steel is still commonly used in implants which will be placed under heavy strain. Another plus point for titanium is the fact that it does not contain nickel, making it by far the better option for those with proven or suspected nickel allergies. It is estimated that 10-20 percent of the population is allergic to nickel, which is a massive figure, and it is one of the main causes of contact dermatitis.

surgical metals

What does being a scrap metal dealer entail?

Posted December 5th 2017

Scrap metal is made up of recycled materials that have been left over from manufacturing and consumptions of products that use metals. This could be anything from parts of old vehicles, to surplus materials that have been discarded during the manufacturing process. It does not, however, include gold and silver, or any other alloy that is comprised of more than 2% of either gold or silver.

A scrap metal dealer is someone who deals with the sale of scrap metals and must have a licence in order to do so. Anyone who is a motor salvage dealer, or conducts business, which deals in any part of the buying and selling of scrap metals, may be deemed a scrap metal dealer. There are two types of licence that can be obtained – a site licence, which licenses the holder to buy and sell scrap metal from one or more sites in the local authority area, as well as transporting the material between multiple registered sites, and a collectors licence, which authorises someone to collect scrap metal in the local authority area. A separate licence must be obtained from each council the collector will be operating in and only one of each type of licence may be held in an individual local authority area.

The price of scrap metal may vary widely depending on location and these are often negotiated directly between sellers and buyers, although sometimes you may see scrap metal prices posted online or in publications. In the US, for example, scrap prices can be found in several publication such as American Metal Market.

One of the key benefits in recycling scrap metals is the impact on the environment. The US Environmental Protection Agency conducted research, which found that using recycled scrap metal instead of iron ore can save up to 75% of energy used in production, as well as giving a 97% reduction in mining wastes and 86% reduction in air pollution. These figures are phenomenal and are just a small insight into the benefits of using scrap metals, which can be just as effective as using virgin materials.

William Rowland is proud to include in its portfolio, the purchasing and sales of specialty revert and scrap metal. Our product range includes nickel based alloys, nickel and cobalt irons, nickel, chrome and molybdenum alloys, nickel copper alloys, cobalt based alloys, nickel cobalt alloys, and many more.

turnings scrap metal

The most powerful magnet in the world

Posted October 15th 2017

Although magnetic materials and magnetic fields are naturally occurring, the most powerful magnet in the world is man-made. Reaching a huge 100 tesla, the magnet is over 2 million times more powerful than the Earth’s own magnetic field, and sits in the National High Magnetic Field Laboratory (NHMFL).

In March 2012, researchers at the facility were able to claim that they had created the strongest magnetic field ever, that was non-destructive. The power of the magnet is over 100 times more powerful than a typical junkyard magnet often seen moving cars or heavy pieces of equipment, and 30 times stronger than the magnetic field that comes from an MRI scan.

The Los Alamos facility is one of three sites that form the NHMFL and the current home of the colossal magnet. Weighing in at 18,000 pounds, and with a huge 1,200 megajoule motor generator, it provides researches with a unique tool to use in their study of materials and the effect of magnetic fields on them. Although other attempts have been made to build similar magnets, none have successfully been able to emit a magnetic field without destroying themselves. As such, the magnet at the Los Alamos site is called a multi shot in reference to its ability to be used over and again – as often as once an hour.

The magnet is composed of four electrical circuits and is surrounded by liquid nitrogen, which keeps it at a cool -198.15 degrees Celsius. This is inside a container known as a dewar and it is used to keep the magnet cool and prevent it from overheating. The magnet is so strong that it also emits a loud shrieking sound when in use, caused by the electrical current modulation. It can only be kept on for a few seconds.

magnetic waves

Asteroid Mining

Posted October 6th 2017

Asteroid mining is the removal of raw materials from an asteroid. It is not something that has yet been accomplished, but there have been many proposals and theories on how this could become possible and there are several companies in existence dedicated to this purpose, including Deep Space Industries and Kepler Energy and Space Engineering.

There are thousands of asteroids that pass close to the Earth, and could potentially be used for the purpose of mining. The materials that can be contained in an asteroid include gold, iridium, cobalt, tungsten, aluminum and nickel, as well as numerous others that we use on a daily basis. With modern industrial processes continually depleting out natural reserves of materials such as zinc, tin, lead, silver, gold and copper, the possibility of them being found elsewhere is certainly appealing and one which we should not dismiss. Whilst this may sound quite far-fetched, Chris Lewicki, the president of Planetary Resources and one of their chief engineers, puts it into perspective. ‘It is natural to doubt when you don’t know much about it. Most people read the headline and make assumptions. We are only repeating what has been done throughout history, just in a new environment.’

The new environment, however, that we are looking at is one which is hostile and dangerous, and that we have barely begun to discover. Despite this, those behind the concept of asteroid mining believe that it has the potential to shape our economy for the next century and will be revolutionary in developing our knowledge of space. They emphasise the importance of not only bringing materials back to Earth, but using them in space for further construction and discovery. Space Foundation, a global non-profit organisation believes the results could be ‘revolutionary in benefits to space exploration, and all of us on Earth’.

asteriod mining

Save

Casting Metals

Posted September 7th 2017

‘Casting’ is a process used in metalworking where a metal in liquid form is poured into a mould and allowed to cool in the cavity to form a specific shape. It is a commonly used process for making complex shapes as the use of the mould allows for great detail and it is more economical than other processes might be. Once the metal has solidified it is removed from the mould and is known as a casting. Items commonly produced by casting include pieces of jewellery, sculptures, tools and some weapons.

The process of casting has been used for thousands of years, but it has been steadily refined and modern casting can now be broken down into two distinct sub-categories – expendable and non-expendable casting. In the expandable casting process, a temporary mould is used that cannot be reused, whereas in non-expendable casting the mould can be reused. This is then further differentiated by which material and which pouring method is used.

There are a variety of materials that can be used for casting, including non-metals such as sand and plaster. If using metal, the most common ones are iron, aluminium, steel, copper and zinc. When casting metals, a non-expendable method of casting is commonly used. For example, permanent mould casting uses a reusable mould, usually also made of metal, to cast metals such as iron, zinc, tin, aluminium and copper, amongst others. Usually, gravity is used to fill the mould, but vacuum or gas pressure can also be used. Another popular method is die casting which pushes molten metal into a mould using high pressure. Die casting usually uses non-ferrous metals such as zinc, copper and aluminium alloys, but it is also possible to use ferrous metals, although they are less common.

It is possible for defects to occur during the cooling period, also known as the solidification process, such as gas porosity and solidification shrinkage. Because of the nature of the casting process, it is difficult to do anything to prevent these from occurring so proper steps should be taken throughout the process to combat these. Shrinkage, for example, usually happens when the metal cooling in the mould is less dense in its liquid form, meaning as it cools to a solid the density decreases. In order to prevent this a suitable metal should be used.

casting metal

Metal and Armour

Posted April 18th 2017

Plate armour was historically worn in Europe during the late middle ages. Inspired by the Greeks and Romans, who both used partial armour plates to protect important areas such as their chest, it began to be used widely from the 13th century onwards.

A full set of armour was incredibly complex, consisting of many different parts, and good sets were highly prized. Steel was the main material used, and each individual piece would be shaped and hammered out by hand before being polished to a high shine and often finished with intricate detailing. A typical set of armour could weigh between 15-25kg but a good smith would ensure this was spread throughout the body to enable the wearer to be able to move freely.

Elaborately decorated armour was common for royalty, often called parade armour, and could include fine embossing in different colours. Particularly fine sets would be immortalised in paintings or even kept on show for visitors, such as the Line of Kings at the Tower of London which displays an impressive array of royal armour in the world’s longest running visitor attraction.

Jousting armour was another type, and this was usually substantially heavier than a typical set of plate armour to withstand the heavy blows it was expected to encounter. As the wearer was seated on a horse, there was also less need for free movement, although it still needed to be light enough to be carried by the horse.

As weapons developed and firearms became more commonly used, traditional plate armour became useless for the most part. Modern body armour is now usually made from synthetic fibres, replacing the traditional steel plates. Ballistic vest are usually made from Kevlar since its introduction in the 1970s, although sometimes trauma plates may also be used made of steel or titanium.

Low melting point alloys & their uses

Posted February 15th 2017

William Rowland Limited is able to produce a wide range of low melting point alloys at our foundry in Birmingham. We can produce to known industry specifications or alloys that are tailored to meet our customers’ specific requirements.

Fusible alloys

A fusible alloy is essentially a type of metal alloy which can be fused with ease. These metal alloys can be melted at temperatures that are relatively low. They are typically eutectic alloys, meaning they have a sharp melting point.

Fusible alloys are often used as the term to describe alloys that have a melting point which is below 183 degrees Celsius.

What are fusible alloys used for?

Fusible alloys are irreplaceable in a range of applications where their low melting point is fundamental:

  • Tube and profile bending
  • Work holding of delicate or irregular pieces
  • Fusible cores for plastic or composite moulding techniques
  • Fusible plugs for boilers and pressure vessels
  • Fusible safety devices for fire prevention such as sprinklers
  • Lens blocking
  • Rapid prototyping of press tools

 

Most low melting point alloys are bismuth based and William Rowland can produce a range of quality bismuth-based alloys to exacting specifications, including:

WR 47                   Lens alloy – used for Lens blocking

WR 58                   Lens alloy – used for Lens blocking

WR 70                   Bend alloy – used for Tube and profile bending

WR 137                 Press alloy – used for Work holding, fusible cores

Bend alloy – WR 70

One type of low melting point alloy William Rowland produces is bend alloy (WR 70).

Bend alloy is one of the most extensively used alloys in industry due to its primary characteristic of expansion on solidification from the molten state. This makes bend alloy an ideal material to support metal tubing with thin walls during bending operations.

The alloy has a sharp melting point of 70 degrees Celsius and can consequently be melted with hot water.

Lens alloy – WR 47 & WR 58

Lens alloys are part of the group of bismuth-based ‘fusible’ alloys. Indium is added to the alloy in order to give it a considerably lower melting point. Lens alloys are eutectic alloys, characteristically possessing a sharp melting point at 58 or 47 degrees Celsius. This low temperature is ideal for acting as a ‘button’ or holding medium in the grinding of lenses.

Possessing stable characteristics, and being easy to melt, lens alloy can be reused repeatedly if required.

Primary use of lens alloy

The primary use of lens alloy is in grinding operations when it proves invaluable in holding glass or plastic lenses. WR 47 is best suited for plastic or composite lenses, whilst WR 58 is used primarily for glass. Due to its low melting properties, lens alloy is also a suitable component in the fuses of safety equipment. Lens alloy can also be effective in proof casting.

Press alloy – WR 137

Press alloy is considered close to eutectic having a relatively sharp melting point at 138°C. It has greater hardness and tensile strength than other fusible alloys and lends itself to anchoring, work-holding and low volume presswork. WR 137 exhibits minimal expansion upon solidification from the molten state, this is useful for holding machined parts where shrinkage or expansion may deform the finished part.

Casting alloy

Casting alloys are a range of low temperature alloys based on tin, lead or bismuth that are suitable for production of jewellery, models, figures, artwork, collectibles, ornaments and memorabilia.

William Rowland produces many different grades of casting alloy to suit the customer’s process and production requirements, however we will also produce to a customer’s individual specification. Our casting alloys are suitable for the professional or hobbyist and we produce many grades that are safe and easy to work with using only the minimum of basic equipment.

Lead-free pewter alloys are popular for jewellery, artwork and collectibles where reproduction of fine detail and cast finish are important, as well as being safe for human contact . These alloys are commonly high in tin and alloyed with copper and antimony. As-cast finish is very good and cast objects polish very well to a silver lustre.

For applications in which lead can be tolerated, the range of alloys is extensive, generally providing cheaper alloys but ones which can be tailor-made for specific purposes such as thin or bulky items, reproducing fine detail, malleability or achieving a particular surface finish. These alloys commonly contain tin, lead and bismuth but may also contain antimony and zinc.

William Rowland casting alloys are suitable for a range of casting techniques such as centrifugal and gravity casting into rubber or silicon moulds.

Contact us today for any requirements of low melting point alloys.

LMPA

‘Tis the Season

Posted December 20th 2016

As Christmas looms on the horizon, most of us have embraced the festive spirit with reckless abandon and succumbed to the tradition of decorating our homes with trees, tinsel and as many flashing lights as we can stand.

The tradition of using tinsel as a decoration is one that can be traced back to the 1600’s. Made with the intention of mimicking ice, tinsel was originally made of strands of silver – perfect for emitting the sparkling effect that ice would in real life. However, as silver can be quick to tarnish other metals were eventually substituted with tin and even lead having been used combined with silver.

By the early 20th Century tinsel had increased in popularity and was used to decorate sculptures and trees, as well as various areas of the home. Improvements in the manufacturing process allowed mass production of cheap aluminium based tinsel for a while, until World War 1 curtailed production.

During the 1950s normal production resumed and tinsel once again gained popularity as a Christmas decoration. As previously mentioned, lead was a popular material for several decades due to the fact it did not tarnish as easily as silver. In the 1960s, however, its use was phased out in the face of concerns about lead poisoning. The American Food and Drug Administration (FDA) released a statement in August 1971 concluding that lead tinsel posed on unnecessary risk to children exposed to it. After 1972 manufacturers began to stop producing lead tinsel, although the FDA did not actually place a ban on it. As they did not have enough evidence to support this at the time they declared it a health hazard instead and encouraged people to stop using and importing it.

Today, the tinsel we see if generally made from a film coated with a metallic finish, known as polyvinyl chloride, or PVC. Whilst they may not be as heavy, or easy to hang as the older metal tinsel, they come in many colours and sizes and their popularity endures.

tinsel used to be made from silver

LMEprecious – What is it?

Posted November 11th 2016

LMEprecious is a new initiative created by the London Metal Exchange (LME), the World Gold Council and a group of leading industry players, which will launch a new set of precious metal products and broaden the offering for the precious metals community.

Set to launch in the first half of 2017, LMEprecious will comprise spot, daily and monthly futures for gold and silver with all trading to be centrally cleared on LME Clear. Developed in response to a demand from the market it will deliver greater choice for market participants, modernising both the gold and silver market to reflect the current need of global players.

The LME’s Head of Business Development has advised this will not render the London Bullion Market Association (LMBA) gold and silver price benchmarks obsolete. He poses the opinion that both markets can work alongside each other, saying ‘I don’t think we should be scared about introducing new benchmarks to the market because of fragmentation. This is a hugely vibrant market and the market will ultimately arbitrage out of the difference’.

According to the LME wesite, key features of the gold and silver contracts will be:

  • A highly flexible date structure – Gold and silver can be traded on a daily basis, from T+1 (TOM), T+2 (SPOT), through to T+25. LMEprecious also offers standardised monthly futures contracts, out to five years.
  • Tradeable carries between all future dates – Including the crucial TOM/NEXT carry trade for inventory management, and monthly roll trades for funds and other investors.
  • Displayed electronic liquidity from day one – The LME’s market-making partners will deliver deep and tight executable prices across the gold and silver forward curves
  • Loco London delivery – Gold and silver bullion physically held in London allows for the efficient settlement between LMEprecious and OTC market deliveries.
  • Optimised capital management – LMEprecious contracts are cleared by LME Clear, the LME’s custom-built metals CCP, with scope for material capital savings.
  • Flexible booking model – LMEprecious contracts can be traded electronically via LMEselect, and through the 24-hour telephone market.

The LME has not traded precious metals since the 1990’s but this is a step in the right direction for them, with plans to add platinum and palladium in the latter half of 2017. Aram Shishmanian, CEO of the World Gold Council (WGC), commented, ‘Over time this will be viewed as a new era for the London gold market. Gold has become a financial asset again – the underlying message is gold needs to be mainstream.’

LME

UNHEALTHY METALS

Posted October 25th 2016

Not long ago we looked at what metals are considered ‘healthy’ and can be beneficial to us. This time we are going to look at metals that can be ‘unhealthy’ or harmful to us if we are exposed to them in the wrong way. Many of these are well known, and of course can still be used as long as they are handled with the proper care and attention. If you regularly come into contact with these metals, or work with them, it is incredibly important to make sure you adhere to any safety guidelines.

Lead

Lead may have a negative effect on human health in any measurable form, which means it should always be handled with the utmost care. If ingested or inhaled in any amount it can be poisonous and causes damage to the nervous system. Lead is still used in building construction, as well as lead-acid batteries, solders and bullets. If working with lead, the National Institute for Occupational Safety and Health (NIOSH) has recommended an exposure limit of 0.050 mg/m3 over an 8-hour workday.

Iron

Iron is essential to our health, however, an excess of iron intake can be detrimental to us. Iron poisoning can occur although it is mainly associated with young children who have consumed large quantities or iron pills inadvertently. It is important for iron pills, generally taken by pregnant women, to be kept out of reach of small children.

Lithium

Lithium is often used in medical treatment, specifically to treat bi-polar disorder. In high doses lithium can be toxic and it is important for medical practitioners to carefully monitor patient’s dosage for this reason.

Manganese

Manganese is a nother metal that has become an active issue in workplace safety. Chronic exposure can lead to negative psychiatric effects and motor disturbances with the symptoms being similar to Lou Gehrig’s disease and multiple sclerosis. There have been several product liability lawsuits against manufacturers of arc welding supplies for manganese poisoning.

Mercury

Mercury is used worldwide in things such as thermometers, barometers, fluorescent lamps and float valves. Concerns about the toxicity of the element have led to mercury thermometers being largely phased out in favour of alcohol or galinstan instead though. Mercury poisoning can occur through inhalation or ingestion and can affect the brain, kidneys and lungs. The export of mercury from the European Union has been prohibited since March 2010 in an effort to limit the use of mercury for health reasons.

 

shutterstock_415155970