Assorted Metal Tubing (approx. weight 2.5oz) These packs contain brass and copper tubing that can be used as small cutters for Art Clay. Can also be used as a fire-in-place option for hinges or embellishments with Art Clay Silver. Brass pieces must be fired below 1400°F but Cooper pieces can be fired with clays up to 1780°F. CAUTION: If aluminum pieces are found in mixture, DO NOT use them with Art Clay Silver. Aluminum may react with Art Clay Silver.