When the small component of an assembly can be placed on the bottom and the large component on top, it is a simple matter to hold the small component in a recessed lower electrode, as shown in Figure 2.13. However, a problem is created when the design requires placing a small part on top of a larger part. Sometimes the small component can be located and held by a removable device and then welded with a flat upper electrode. Components that nest into the upper elec
trode may be held by spring clips attached to the electrode. Figure 2.14 shows a spring-loaded retainer entered through the side of the electrode holding a bolt for welding. A vacuum also may be used to hold small components in the upper electrode when component design permits.