Starrett TCT Multipurpose hole saws are constructed with tungstun carbide tipped teeth for outstanding cutting performance and and durability. They will power through wood, MDF, plasterboard, plastics and ceramic wall tiles up to five times faster than a bi-metal hole saw. They have a cutting depth of 54mm which allows the cutting through joists and strapping. Select an arbor with a carbide tipped pilot drill for extra life or if using a HSS pilot drill, ensure it's the extended type.