Hardin HD-334MC2 2kg Graphite Crucible for HD-334MF furnace. Ideal for someone who is only looking to melt several batches of material at a time. It is used to hold your precious metals such as silver, gold, and copper while they are melted at high temperatures needed in order to cast into bars and ingots. Has a little groove at the top to easily grab with tongs. It's recommended that you never fill the crucible to more than a 2/3 to avoid spillage. This crucible can be used multiple times when handled with care. Oil from your hands will speed the corrosion process after heated.