Machining is a standard in many industries, especially in areas that require high precision and minimal tolerances. On top of the obvious users – like airplane or automotive industries – the manufacturing of medical supplies is very often executed with the usage of numerically controlled devices. CNC turning or milling (often with advanced 5-axis milling machined) provides high quality and efficiency for manufacturing medical equipment.
CNC in production for the medical industry
The contemporary medical industry requires the highest possible precision and accuracy on top of the repeatability of production. Thanks to these features electronic devices, surgical equipment, and prosthetics elements can be used efficiently and comfortably. Key duties of the healthcare industry – like saving lives and maintaining its quality – are easier to achieve with well-manufactured tools.
Today's machining can provide strong support for many industries – medicine among others.
CNC devices can manufacture precise elements of bigger devices or systems focused on even the most advanced and precise microscopic surgeries.Without these parts, such operations would not be possible. The contemporary medical industry uses CNC machining services in the following applications:
- in manufacturing surgical equipment, especially out of chemically stable alloys – such as steels (200, 300, 400, and 500 series, with a strong emphasis on the usage of 316L alloy, commonly called 'the surgical steel'), like like scalpels of surgical scissors,
- in manufacturing micromedical tools – used (for example) in laparoscopes – due to the required high precision, repeatability of production provided by CNC devices can deliver more than satisfying effects. On top of that – strict quality control helps to maintain interchangeability between batches of parts,
- in manufacturing parts of prosthetics (limb or tooth) that require high precision of production and machining – often non-standard – threads,
- in manufacturing parts of bigger systems – like housing frames for medical devices like CT or MRI scanners, often out of non-magnetic alloys or polymers,
- in manufacturing a vast variety of elements out of polymers and plastics – for example, couplers made out of chemically stable materials that can be easily cleaned with aggressive disinfectants,
- in prototyping – although CNC machining allows quick and efficient mass production, it is – a first glance – not the perfect solution for prototyping. On the other hand – due to the requirement of high precision and availability of technology, CNC remains an often selected technology for medical prototyping (sometimes supplemented with 3D printing).
To sum up listed applications of CNC machining in the medical industry – the more precise and specialized the medical equipment is, the type of manufacturing process is suited for the job.
Advantages of machining medical parts with CNC
To be blunt – the advantages and possibilities provided by CNC technology are the main reasons why the medical industry uses it broadly. There is no stretch in declaring numerically controlled devices as an industry standard for medical parts manufacturing – just like in aviation or space.
The advantages of CNC machining that make such a perfect fit are as follows:
- highest level of manufacture precision – contemporary CNC devices allow the production very complex parts and tools, often miniaturized, with maintaining minimal tolerances, that can be easily replaced and provide precision of operation,
- high repeatability and speed of manufacturing – CNC technology allows the mass production of parts that (with the help of meticulous quality control) can be called practically identical. That is why can be easily replaced and remain an integral part of bigger systems,
- possibility of machining a vast selection of materials – steels are not the only material used in the medical industry. Contemporary CNC machining devices allow also shaping other alloys, ceramics, composites, or polymers,
- broad possibilities of forming material – numerically controlled machining devices allow the manufacture of parts of almost any shape. Combined with electrical discharge machining can help to produce even the most complex parts,
- possibility of achieving – on average – low unit cost in mass production,
- possibility of scaling the manufacture up and launching new batch production almost on the spot (often called 'manufacturing on demand').
Materials used in machining medical products
The medical industry is often associated with steel – it is one of the oldest known alloys, broadly used from the dawn of modern medicine (and – earlier). Good mechanical parameters make it a perfect material to make blades or medical equipment. That is why many people connect 'surgical steel' with rigidity, precision, and a very low possibility of causing allergic and/or anaphylactic reactions. In such 'surgical steels' groups are often placed four main series of steel alloys with additives of chromium, nickel, molybdenum, and manganese (of vast proportions – from 200 to 500 series).
It is worth mentioning that the 300 series has the best natural corrosion resistance.
Currently, that material is the most often used in manufacturing surgical equipment, prosthetic parts, or even orthopedic screws to hold together broken bones. Due to very high chemical resistance, the material can be regularly disinfected (eg. in an autoclave) and subjected to very aggressive cleaning agents. Such stability translates also to a very low possibility of causing allergic reactions, even for surgical steel alloys with additives of nickel.
The nickel itself can cause very strong allergic and anaphylactic reactions that can be dangerous for people with intracorporeal prostheses or mentioned orthopedic screws.
But as an additive to an overall chemically stable alloy, it can remain neutral for the human organism.
From the manufacturing perspective, surgical steels have good machinability and can be cold-formed (to some extent). The development of metallurgy – and the medical industry itself – caused a visible shift from steel to titanium alloys. Many applications can be even more wanted, especially due to low mass, good machinability, mechanical properties, and above all – very high chemical stability. That translates to a low possibility of causing an allergic reaction. Titanium parts – made in CNC machining devices – are often used in internal prosthetics (eg. 'titanium plate in the skull' or 'titanium screws in the hip') and precise parts for the (neuro)surgical equipment.
On the other hand – the separate prosthetics industry (as for the internal and the external devices) broadly uses polymers, carbon fiber, aluminum, and titanium alloys. These are the materials that are often used in contemporary (and modern) prosthetics. That industry requires possibly the lowest mass and the best possible mechanical properties of materials to provide the best performance of devices that should replace – for example – lost limbs. And to help to return to normal life for a person who needs it.
Light aluminum and titanium alloys – often subjected to the additional galvanic processing, to improve its rigidity – are used as load-bearing elements of the prosthetics. Polymers and fibers (carbon, glass) are used to form the body. Low tolerances provided by CNC machining for medical instruments or prosthetics provide the possibility to use it even more efficiently.
On the other hand – the selection of the right materials and the right assembly translated to higher comfort of usage and better longevity.
Medical prototyping and mass production
CNC machining is used all over the world for medical equipment manufacturing. In particular – for mass production, often due to repeatability and the possibility of manufacturing identical bathes on demand. On the other hand – 3D printing has more and more applications in a vast variety of industries, including medical, especially for quick prototyping. The road from the prototypes (in CAD software) often leads through the 3D printed prototypes that can be examined and analyzed; but still: the final step is ordering a CNC machining for mass production.
Such a process is more and more often, especially due to decreasing the development cost and the possibility of significantly speeding up the whole process. It is worth mentioning that the CAD files – used for the digital prototyping – are a canvas for the 3D printer prototypes and final translation for the CNC-specified G-code and manufacture on the numerically controlled devices.
One order, many benefits – this is how you collaborate with RADMOT
At RADMOT, we offer CNC milling services, CNC turning services, as well as many additional services, including washing, aluminum anodizing, laser marking and assembly. We have at your disposal over 80 modern machines in our machine park, all from renowned manufacturers. Download the presentation and check on which machine tools we produce CNC turned parts and CNC milled parts.
Contact us and tell us what you need. We have been providing CNC services for almost 40 years. Our valuation is completely free. And if you're in doubt about which technology will work best for you, our expertise is at your service.
