Coolant and lubricant circuits are required for ensuring component function in a variety of different areas and applications in the automotive industry, from gearboxes and pumps to engine blocks. These have to be closed and sealed.
Usually, screw plugs (with or without under-head seal) or expander solutions are used for sealing holes. In contrast to screw plugs, expanders cannot be removed without being destroyed.
In addition, these sealing elements close off the hole, but require complex preparation of the bore hole.
For example, the process of drilling, countersinking, milling the head contact surface and cleaning the thread when using screw plugs is very time consuming and expensive.