Socket Types for Ratchets

In professional workshops or backyard week-end repairs, we need to use sockets with ratchets to install or remove fasteners (bolt or nut).  These sockets come in various sizes and types.

From left to right, the image below shows the three main socket types, i.e., 12-points socket, 6-points socket and a side-grabbing 6-side socket. The 8-points sockets,  used with rectangular nuts, are not so common.   

Here is how a 12-points sockets grabs a nut. It obviously grabs it from corners and may round-off the edges of the nut if tightened too much. On the other hand, a 12-points socket is easier to fit on the fasteners than the 6-points socket. It is primarily used in the aerospace industry where fasteners are installed in tight places and which are difficult to access. Also it is the only option for bolts with 12-points head.

Below is a traditional 6-points socket, which grabs the nut entirely rather than just the corners (as a 12-points socket does).

Here is a side-grabbing socket for hex nuts and bolts. It does not grab the corners and therefore is suitable for nuts / bolts whose corners are already damaged or if one does not want to take the risk of rounding-off the edges of fasteners.

If you have, by accident, rounded off your bolt or nut (hexagonal), then these standard sockets will not work and a special socket (for rounded off fasteners) needs to be used.