Abstract: A socket accommodates pipes of different wall thicknesses that are to be joined by a fillet weld. The socket has a body with a central opening in one face. The face includes a series of physical indicators each of which are spaced from the opening a distance corresponding to the proper fillet height for one of the pipe wall thicknesses. The indicators may be a series of steps, protrusions, or grooves. The socket may be formed in an adapter to join pipes to another member, or the socket may be formed integral with a member such as a valve body, a flange, or a pipe connector.