We are getting more people asking
about welding nuts to parts. We are finding that the majority of these
people do not realize that there are specialty electrodes already made for
Again I will refer to the CMW catalog for tables and pictures
concerning this style of tip.
The nut electrodes fall into two catagories: self-piloting
and non-piloting (spring loaded).
The drawings below illustrate these electrodes, but I
will try to describe it also in case the drawing is confusing. This
electrode is made of copper with an elkonite facing on the weld surface.
This facing increases the tip life since it is more wear resistant than copper.
The self piloting nut electrode has an insulated pin that the nut fits over
for locating it (see figure 1). The non-piloting nut electrode has
a spring loaded insulated pin to locate the nut, but the pin pushes down
when the upper electrode comes down. (see figure 2). The pin returns to the
upright position after the weld is complete.
The electrode number is determined by the diameter of
the electrode (O.D.), the nut you are going to use, and whether you want
the solid pin or the spring loaded pin. You will find the table below for
both these styles.
Self piloting or solid pin
Spring loaded or non-piloting
A special external cooling chamber can also be added for
additional cooling of the electrode. These cooling chambers fit over
the OD of the electrode. These are not mandatory, but can be usefull.
The nut electrode is usually the lower electrode.
The recommended upper electrode is called a "back up electrode". I
would recommend using a elkonite back up electrode for the upper electrode
when you have an elkonite lower electrode. The diameter of the back
up electrode should match the diameter of the stud electrode. I would
back up electrode
632050 or 832050
632050 or 83205
16-3775 - xxxx