Human beings cannot survive without machines today. Most of the products that require mass production or precision are manufactured using machines. In many cases, especially in the manufacturing sector, the final product itself consists of machined components.
Machining is a process that uses tools like milling, shaping, drilling, etc. to work on raw material to give it different shape or size. Machined components are widely used in all industrial products. They came to the fore after the industrial revolution of the 18th century.
Machined components are made from ferrous and non-ferrous metals. They can vary in size from a small watch gear to a gigantic turbine. They are used:
- For components that require flatness, roundness or parallelism for their proper working
- Where components need to mesh or move each other in a precise manner
- In machines that require precision and high dimensional accuracy
Machined components can be classified in the following way:
Single Machined Components
Single machined components are those that are made of a single material. These components have a homogenous shape. Examples of single machined component include castings and sintered components
Joined Machined Components
There are two types of joined machined components. The first type consists of at least two single components connected together by processes like welding, soldering, rivetting, pressing, etc. The second type consists of single machined components that are made of several materials like compound castings, bearings, etc.
Assembled Machined Components
As the name implies, assembled machined components consist of several components joined together by suitable binders like screws, pins or spring fits. These components mostly form a functional unit. An example of assembled machined components is split castings.
Machined Components Considerations
The primary considerations for machined components include material type, the main machining processes, and the type of machining used. Machining is essentially a process of removing material by the application of mechanical energy to machine tools. The basic processes used for machining are turning, milling, drilling and grinding.
A few other things to consider in manufacturing machined components is the amount of scrap / waste and the amount of electrical energy consumed. Many a mechanical process tens to create a lot of waste in the form of solid, liquid and airborne particulates, something that needs to be minimized.
The designing of machined components is a very important consideration. In general, the design cost is only about 5% of the actual production cost of the machine component. However, properly designed machined components can save as much as 50% of the production cost. Properly designed machined components should:
- Reduce the number of parts required – this ensures reduction in production cost and fewer complications
- Use modular designs – to simplify the final assembly
- Optimize part handling – so that assembly is easy and standardized
Machine components are the heart and soul of the manufacturing industry. Turbines, automobiles, airplanes, ships, windmills, railways all contain machine components.
Most machines are made of parts called as elements. These elements can be classified as general purpose (e.g. nuts, screws, bolts, flanges, etc.) and special purpose elements like crankshafts, flywheels,rotors, windmill hubs, valve bodies, etc.
There is huge scope for machined components, and a wide gamut of raw materials available. A few speciality materials are mentioned below:
Austenitic Stainless Steels
Austenitic stainless steels are the most corrosion resistant types of steel. They contain nickel and are nonmagnetic. The food and chemical industries use machined components made from austenitic stainless steels to prevent product contamination that would result from corrosion.
Ferritic Stainless Steels
These steels have low carbon. As compared to austenitic grades, they are less resistant to corrosion but are more economical to manufacture. Machined components manufactured from ferritic stainless steels are used in automobile exhaust components.
Martensitic Stainless Steels
Martensitic stainless steels have high carbon content. They can be made harder by heat treatment processes. Machined components that use martensisitc stainless steels include surgical equipment and knife blades.
Nickel based alloys that use rare metals are called as superalloys. Since these superalloys are very strong, can resist high temperatures and highly corrosive environments, they are used in extremely harsh conditions. Machined components that use superalloys include jet engines and fittings that carry hazardous material. On the flip side, machined components that use superalloys are very difficult to produce. In India, only a few quality superalloy machined components manufacturers exist.
Titanium has the best strength to weight ratio of any metal. Machined components that use titanium alloys are used in the construction of aircrafts, spacecrafts and racing motor sports. One more titanium machined components find is in joint implants like hip and knee replacements. Again, only a few in India manufacture machined components made out of titanium alloys.
Machined Components in India
There is a growing demand for machined components throughout the world. Europe (especially UK, Germany and France) and the US are some of the top manufacturers of quality machines. These machines have a demand in all parts of the world due to their precision and longevity. However, these manufacturers find it economically unviable to produce all the components themselves due to various reasons. These manufacturers prefer to outsource the manufacturing of these parts to countries that are economical, but still offer the precision that they demand. India, with a developed infrastructure and skilled workforce is therefore a popular choice for outsourcing machined components. In addition, there is a growing demand for quality machined components within India as well.