Manufacture and Application Options of Semi-Finished Products in Mechanical Engineering

Semi-finished products or subassemblies very important components in the industry. They are the intermediate step between raw materials and the finished end product. Therefore, they are important for many companies in the manufacture of their products. Without semi-finished products, companies would have to process the raw materials for their products themselves. This article explains how semi-finished products are manufactured and where they are used.

What are semi-finished products?

Semi-finished products - also called subassemblies - are processed raw materials or intermediate products between raw material and end product. Raw materials are materials that come directly from nature and are not subject to any processing. As soon as the raw material is processed, it is characterized as a semi-finished product. Semi-finished products generally consist only of one material that is made into a coarse shape. As soon as further production steps are carried out, e.g., to create an individual shape, this is referred to as blanks. Semi-finished products can be made of metal (steel, copper, aluminum), plastic or other materials.

Manufacturing processes and processing of semi-finished products

Semi-finished products are produced, for example, by the following manufacturing processes:

primary forms

The primary forming manufacturing process is the first step in the production of semi-finished products. DIN 8580 defines primary forms as the first main group of manufacturing processes and then divides these into eight additional subgroups. During the primary forming process, a formless (raw) material was transformed into a shaped body. Primary forming is used in production technology to produce the initial form of a material and, for example, to ensure the material cohesion. In addition to pressing, injection molding and extrusion, there are numerous other primary molding processes.

During pressing, a moldable material (e.g. metal powder, plastic granulate) is shaped by pressure application. In most cases, the component that is created is then subjected to heat treatment to further solidify or harden it.

Extruding can be used to create components that have continuous profiles, such as pipes or rods. A mostly plastic material is pressed through a forming nozzle applying pressure and temperature, thus obtaining the desired appearance.

Injection molding is particularly suitable for plastics. The granulate available as raw material must be plasticized during the process, i.e. it is brought into a flowable state by heating. These so-called melt is then injected into the injection molding tool, where it cools and is later demolded. The cavity inside the injection molding tool also determines the final shape of the workpiece.

Further processing: machining of semi-finished products

Semi-finished products are often further processed by machining or forming. According to DIN 8580, forming is a separate main group of manufacturing processes. Machining is part of the main group of cutting. Machining is one of the most important manufacturing processes in the industrial sector. The following example for the production of a precise aluminum tube describes various production steps. In a first step, the finished semi-finished product is selected. Aluminum pipes are classic semi-finished products. They can be easily procured. They can have standardized dimensions or already have dimensions adapted to their actual application. This is particularly relevant if it is imperative to comply with standards. In the case of standardized dimensions, in a next step, the aluminum pipe is cut to the desired length of the end product.

Now it is machined: bore holes can be drilled for assembly or connections. In addition, the ends of the pipe can be flattened by milling to provide a better seal or fastening. Depending on the application, it may also make sense to cut a thread into the pipe with a thread cutting tool. After machining, the surface treatment may follow to protect the pipe from corrosion and other external influences. At the end, quality control and assembly with additional components will follow.

Potential Applications for Semi-Finished Products

Semi-finished products are used in mechanical engineering, e.g. as precision components. Precisely manufactured components can be produced by using blanks such as pipes, sheet metal or rods and they can be used in machines and mechanical systems. Semi-finished products are also suitable as structural components such as frames or housings.

In the following example, a workpiece transport cart was assembled from a series of aluminum sections:

The aluminum sections can be machined. In addition, aluminum sections and accessories can be configured at MISUMI and then ordered appropriately. This option reduces the number of development steps.

In the first step, it is important to check whether the aluminum sections can withstand the mass of the transport objects. More details on the evaluation of the main components of this example can be found under this link.

In the MISUMI Web Index, you will find further information on calculating the deflection and load capacity of the aluminum sections offered by MISUMI.

You can find more interesting design examples in our inCAD Library.

Semi-finished products at MISUMI

MISUMI offers a variety of semi-finished products made of various materials:

• metal plates, also adaptable to various applications
• round bars, rods and pipes
• angles and section steels
• semi-finished products made of plastic (plates, panes, covers)

Metal plates are an essential semi-finished product in mechanical engineering. They can be used as a basis for load-bearing structures or assembly tables or they can be further processed into machine housings and components.

MISUMI has metal plates made of a variety of materials, e.g. aluminum, steel and copper. There is something for every application through a wide variety of designs (plates, blocks, L-shape, concave blocks, round blocks, flat bars).

In addition to unmachined metal plates, there are generally also machined metal plates and sheet metal parts offered. Here, important preliminary work, such as one first surface treatment, is already completed in advance. This is available for mounting base plates, mounting plates and brackets. Round bars can act as a base for axles, shafts and bolts. In addition to many other application areas, pipes are installed in various industries for the transport of liquids and gases. MISUMI has pipes, rods and round bars that can be freely configured in terms of length and diameter, ensuring a high degree of accuracy. Metal and plastic versions are available.

In addition to metal plates, there are also plates made of plastic as well as plastic discs and covers. In addition to metal, subassemblies made of plastic are one of the most important materials. They can be used as insulation material to protect electrical components or as covers to protect against environmental influences and damages. Subassemblies made of plastic are available in a transparent and non-transparent design with additional options such as bore holes. The following are also available: ceramic plates or visual inspection connections.

Other semi-finished products offered at MISUMI are freely configurable angles and section steel, especially L-shaped angles, U-profile steels or strand profiles made of steel and metal crates. Angles are suitable, for example, for strengthening and connecting structural elements or for carrying heavy loads (section steel). The U-profile steel semi-finished products made of aluminum are available in lengths from 30 to 1000 mm and numerous widths and strengths. They can be supplied with mounting holes. Metal crates are available in freely configurable sizes, including corresponding mounting plates made of stainless section steel.