Dowel pins are among the simplest types of fasteners available in the market. They feature cylindrical-shaped solid materials that are utilized to join or align many parts. They are available in different materials. Dowel pins are made of wood, steel, plastic, or aluminum. Regardless of the material, they all have a similar design. They are available in both imperial and metric units. These pins are designed to align the machine parts effectively. They can also be utilized as location guides for adjacent machine components. They can maintain the two sections of a punch and die in alignment.
Dowel Pin Operation
Dowel pins do not consist of any actuated parts. Their mechanical capabilities come from their high coefficient of friction, and any kind of adhesive that is applied when they are inserted in pre-drilled holes. It is important for the pins to be rigid so that they can keep the assembled parts aligned without any further need for hardware fastening. To create a firm connection, it is essential for the hole to be the same size as the pin. There are different working loads of dowel pins that are measured with their breaking strength when a double shear happens.
For applications where the hardware is exposed and you want it to be aesthetic, a dowel pin can appear uniform to its assembly. However, this is a differentiating advantage of these pins over other pins. Due to such benefits, dowel pins are commonly preferred for furniture. You can also use them as axles and hinges.
Manufacturing of Dowel Pins
The wooden dowel rods are manufactured on the same mill machinery that also produces other cylindrical wood items such as furniture pieces and fence poles. Dowel pins are usually the shorter versions or lengths of the full-size dowels. These pins are common in hardwood such as maple or birch. These pins can also undergo a second operation if desired. Metal pins are known to undergo a process of melt and cast.
The common materials used for manufacturing dowel pins include:
This material has many benefits for producing pins. It is ductile, light, conductive, and highly resistant to oxidation.
This also has a number of beneficial properties for producing dowel pins. It is strong, conductive, ductile, corrosion-resistant, and has low magnetic permeability.
Usually has a high chemical rating and is resistant to chemicals and corrosion.
Pins that are made from hardened steel produce a very tough metal which is also brittle. This normally goes through a hardening process like induction. Unhardened steel is malleable however, it is appropriate for many applications.
It is usually very strong and durable as well as resistant to temperature and corrosion. These are 44% lighter than the steel pins.
Plastic dowels are produced through plastic injection molding,
Sizing of Dowel Pins
After you consider the materials, pin sizing is an important factor that the manufacturers should consider.
This is the measurement of the length of the dowel pin across its length.
Usually a measurement of the pin’s longest cross-section.
The majority of dowels are manufactured from the straight dowel variety. A dowel usually has diameter tolerances of ± .010 inches in contrast to the nominal size. This tolerance value is important because it will ensure that the pin properly connects to the hole.
There are not many types of dowel pins. Cotter pins, locating pins, and spring pins have their own selection guide as well as specification filter. A straight pin that features metric or SAE threads is known as a threaded rod.
Drive pins commonly have an interface fit and are fitted into the hole by using a hammer. They are for moving and rotatory applications.
Groove pins consist of longitudinal grooves. These grooves are useful for the adhesives to release hydraulic pressure and improve holding.
Knurled pins feature a surface that can improve the dowel pin’s grip. It is commonly utilized for decoration or when parts are locked together in certain assemblies.
Pull Dowel Pins
Pull dowel pins consist of a threaded hole at one end of a screw and be installed to guide removing the pin from the hole.
Spiral-Groove Dowel Pins
These pins consist of helical and longitudinal grooves. They offer expansion space for adhesive and also give more friction.
These pins are tapered and have a rate of 1/4″ per foot that can range from the larger to the smaller diameter.
Threaded Taper Pins
Finally, these pins are very similar to the standard threaded pins. The only difference is that they consist of helical grooves along with one of the diameters.