Blades are stainless steel with a diamond-grit edge that cuts hard, abrasive materials such as carbon fiber, ceramic, masonry, glass, composite, quartz, and silicon. They're not for use on metal. Use them on materials of any thickness. Choose finer grit for less material loss and a smooth finish; choose coarser grit for fast cutting. Blades have a welded seam and are ready to install on your saw. Use coolant (not included) when cutting masonry, glass, quartz, and silicon.