Dowel pins are small, solid steel tubes that resemble traditional wooden dowels.
They are manufactured to a very high tolerance to ensure that they are a precise fit. They are generally used for locking components in place.
Dowel pins are available in metric sizes. The diameter of a dowel pin is obviously the most important dimension but don’t forget to check the length, as unlike wooden dowels they are very awkward to cut to size.
Dowel pins are available in size increments of 1mm diameters.
Metric is the most common thread type in production today. Usually specified as M then a number x another number. This signifies the thread diameter and the length of the fastener.
For example M4 x 30 means that the major thread diameter (the external distance across the outside of the thread) is 4mm and the length is 30mm. Length is usually measured from the underside of the fastener head.
Steel products described as having a self colour finish are best suited to internal applications, as they have no additional protection against corrosion. The shade of a self colour finish can vary from bright metal to black, and it will change over time with oxidisation.
If you plan to use self colour finishes outdoors you should paint them to give them a protective coating.
