5mm diameter Index Wood Assembly Screws in Black Oxide (Self Colour) Finished Steel
Socket head assembly screws for furniture construction and joining fibreboard panels. These are a type of self tapping screw, which will cut it's own thread into MDF (medium density fibreboard) or particle board as it's driven into a pre-drilled hole.
The wide diameter of the screw and the very coarse sharp angled thread gives a better hold in these materials than traditional woodscrews.
Assembly screws are also known as furniture screws and confirmat dowel screws.