English (language) A castle is a fortress. It may also have a residence, and many castles were residences of various lords and nobles, but a castle isn't required to be a residence, as many were built to be forts guarding militarily interesting areas. A mansion is a large, opulent residence. It may have a fairly high degree of security and some level of fortification to protect the people living there, but it is not intended to be a strong place with strategic military importance. Written Jun 12, 2015 â¢ View Upvotes.
A plug weld is used to fasten two pieces of metal together using a welder. When joining the pieces, a hole is drilled into the top piece and it is laid over the bottom one. A weld is then made by running a bead inside of the drilled hole, thereby holding the two pieces together.
These cavities are usually the coolant passages. Holes are designed into the casting to support internal sand forms, and to facilitate the removal of the sand after the casting has cooled. Core plugs are usually thin metal cups press fitted into the casting holes, but may be made of rubber or other materials. In some high-performance engines the core plugs are large diameter cast metal threaded pipe plugs. Core plugs can often be a source of leaks due to corrosion caused by cooling system water.