Dowel pins are a common industrial fastener capable of joining two or more parts together. Although dowels may be made of wood, metal, or plastic, they tend to always be short cylindrical rods that are tapered, slotted, or grooved. Since dowels are often used to maintain precise alignment of machine parts or as positioning guides, it is useful to have a basic understanding of these types of fasteners and the various types available in the market.
Unlike many other components, the dowel is completely free of any driving or moving elements. Instead, they rely on their high coefficient of friction to stay within the press-fit, pre-drilled hole they are inserted into, and additional adhesive can be applied for further security. Dowels are also able to appear unified in their components due to the absence of certain elements, making them the perfect solution for furniture and other aesthetically oriented components.
To ensure that all assembled parts stay together without the need for additional fasteners, the dowels selected must be rigid when installed. For the strongest fit, the hole the dowel goes into must be the exact same size or slightly smaller than the dowel. Since dowels already have established breaking strengths that indicate when double shear has occurred, it is important to identify any potential operating loads before making a purchasing decision.
When manufacturing dowels, the process may vary depending on the material and design of the fastener involved. For example, wooden dowels can be produced using the same rolling mills as other cylindrical and wooden products, only smaller in structure and size. Most wooden dowels are made of hardwood and can be planed or grooved as desired.
For metal dowels, the melting and casting process is carried out according to a certain standard process, which starts from the melting and refining of raw materials and ends with various quality checks and inspections. Depending on the application, a variety of materials are available, with common choices including aluminum, brass, stainless steel, steel, and titanium. As a final pin material, plastic pins are often manufactured by plastic injection molding.
In addition to determining which material is best, you should also take the time to consider lead size in terms of outer diameter and length. For outside diameter, people are talking about the measurement of the edge that determines the width. Meanwhile, length is a measurement made on the longest cross-section of a component.
