A machine screw is a type of screw that is commonly used in industrial and manufacturing applications to secure components within engines, electronic products and general machinery.
Countersunk machine screws are designed for installation in countersunk holes to enable them to sit flush within the finished surface. This type of fastener should be installed with a flat-bladed screwdriver or bit.
About Self Colour Metric Thread
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 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.
This section of our guides and tips hub contains a library of helpful articles such as guides to using screws, screw specification sheets and product reviews on different types of screws such as woodscrews, self tapping screws and decking screws. If you can't find the information you are looking for here, please don't hesitate to get in contact with us!