Although “better, faster, cheaper” is often considered to be a product of the 21st century, keeping costs low is nothing new. As the astronaut Alan Shepherd famously once said in the early 1960s: it’s very sobering to be relying on components that were manufactured by “the lowest bidder”– a very sobering thought indeed!
The real skill of an engineer is not being able to design something that is fit for purpose, but being able to design something that meets the required standards without costing a small fortune to manufacture. As one of my engineering friends said during a conversation about the real value of their skills: “Anybody can make something that will do a job, but not everybody can make something that will do a job without breaking the bank.”
Taking a project to production is a fine balancing act that sees an engineer adjust the scales precisely in order to design components that meet the required functionality and integrity within the available budget. This is harder than many people appreciate due to the long list of associated costs that manufacturing processes have. Purchasing departments far and wide know that the cost per unit is determined by material cost, labour costs and shipping costs. The more material that needs to be used, the higher the production costs; the greater number of processes that have to be used to produce a component, the greater the production cost; and the further the components have to travel between processes, the greater the production cost.
Although finding a production method that can reduce the number of stages required in the production process and keeps these costs low may seem as likely as finding a pot of gold at the end of a rainbow, one does exist…
The process is investment casting; one of the oldest metal forming techniques in the world. It has been used in various forms for over 5,000 years and today it is still the first choice process for many engineers working in industries where precision is paramount. Metal castings are formed using the “lost wax process”, which involves wax replicas of the desired component being produced, “shelled” and burned out to produce a mould for the metal casting.
If you are not familiar with the investment casting process, I highly recommend that you take a look at the overview of the process that we have produced. (Another resource that you may also find useful is the handy article that we have created which lists the benefits that are associated with the process.)
Why can investment casting save money?
So, how does this process reduce production costs and save money? Quite simply, the process reduces the amount of material that is wasted when producing finished components, reduces the number of stages that are required to produce finished components, and consequently reduces the amount of shipping that components are subject to during production.
But how does it do this?
The key to the cost savings come in the form of the benefits of the process – which allow components to be produced precisely and accurately.
The freedom of design that investment casting grants an engineer reduces the need for machining processes. The fact that investment casting can be used to manufacture components that have complex designs without having to rely upon subtractive manufacturing methods means that material waste is reduced. When compared to machining from solid (a process for which material waste is a by-product) significant production cost savings can be made. The cost savings can be so substantial that machinists have been known to commission investment casting foundries to produce castings for them to ‘finish’ on behalf of their clients. By having components manufactured as investment castings, many reduce the links in the supply chain that is associated with their project’s production processes.
Although castings may have to undergo some additional processes in order to achieve the necessary production standards, the number of stages involved in production can be significantly reduced. Complex features such as undercuts, cooling fins, cooling pips, PCB guides, sealing grooves, fine detail and lettering can be produced through the process – reducing the need for post cast machining. The fine 3.2 micron ‘as cast’ surface finish that can be achieved through investment casting is often good enough to meet the required standards for most applications. In the instances where it isn’t, surface treatments can be used to improve a castings finish. Investment casting allows products to be manufactured to 90% of their finished state, if not 100%.
Is investment casting really the answer?
Like with most things in life, “one size does not necessarily fit all”. Investment casting may not be the answer for all projects; in some instances other manufacturing processes may be more suited to manufacturing certain components. However, investment casting is the ideal production method for manufacturing complex ferrous and non-ferrous components that have to be lightweight and have good integrity.
It can avoid the material waste that is associated with machining from solid, reduce the need for post casting finishing and save the time and cost associated with redesigning components to make them suitable for a production process. Man power often ends up being a hidden cost in manufacturing, but it is one that can be considerable. Adopting a method that avoids the need for design changes saves time, and as a result money.
Potential cost savings, coupled with the long list of benefits that are associated with investment casting, create a very compelling argument for many engineers to explore the manufacturing process when looking for a production method to realise the components required in their next project. The potential savings may be so great in certain instances, that some would look to see if changing to the investment casting process could save cost on projects that are already in production.
If you have a project that requires complex components to be produced that have good integrity and aren’t subject to expensive and lengthy machining process, you should definitely consider investment casting. Contact our team to see how investment casting can help you achieve the right balance between quality and cost.
