Dowel pins are great for alignment, but in a world where lightweighting is becoming more and more critical, there may be some alternatives to standard hardened and ground dowel pins.
The first option to review is whether fully ground and hardened dowels are required. Is it possible to achieve similar results using pins that don't require as much machining and hole preparation?
Finding an easier way to align mating components may not only be a way to reduce the weight of the finished assembly, but also a way to reduce the overall cost. An alternative to a reamed hole with a dowel is to use a counterbore with a hollow dowel through which a bolt or screw can pass. This is a very efficient way to combine the functions of the drilling required for dowel pins and the functions of the fasteners required to clamp the parts together.
Hollow Dowels and Split Dowels
Hollow dowels are suitable for many applications and have some benefits associated with them. They can be used to reduce the tolerances required for mating holes and reduce overall weight. Hollow dowels can also have openings. This split offers several advantages over seamless hollow dowels. Split dowels are easier to manufacture than seamless hollow dowels and can be used with tolerance bands that do not have the tightness of standard dowels.
Another good alternative to plastic parts is barb pins. These allow material to flow around the barbs to lock in place. If the pin needs to be locked in the metal, this can be done with a knurled or grooved pin. Both pins can be used as pivots as well as for positioning purposes.
