Nitride-bonded silicon carbide kiln shelves are much thinner (5/16"/ 8 mm) and lighter than regular cordierite/mullite shelves. Not only are they are easier to handle but their lower mass saves on heating costs. SiC Shelves stay flatter for longer, even with heavy loads. This is the recommended size for 12-sided top-loading kilns like Euclid's R-280.
Thoroughly dry new shelves before use or if exposed to moisture (such as after kiln wash application) to prevent uneven heating or, in severe cases, rapid build up of steam which , can result in explosive fragmentation; 5 hours @ 100ºC is recommended.
Silicon carbide is electrically conductive so shelves must not contact heating elements. While very strong, these shelves are more brittle; avoid knocks and bumps when handling or placing ware.
Buy 10 of any 1 kiln furniture item & pay 10% less.