Crucible tongs are tools used to lift hot, heavy, and hazardous crucibles in activities like glassblowing and metal casting. The crucible is a container used to hold materials while they melt in an extremely hot furnace. Operators cannot handle crucibles directly because of the intense heat and fumes, so they use tongs to grip the devices while moving and repositioning containers of molten material. A closely related tool is the shank, which is used to control a crucible during pouring.
Typically, crucible tongs are made from a durable metal that can withstand high temperatures. They include locking or latching versions that can be locked on to the edge of a crucible, along with handheld versions without a latch that must be controlled by the operator. They also typically have stops to limit the amount of pressure a technician can exert, to prevent a situation where a crucible might fail under too much pressure.
The handles are long, and may have insulated grips for safety. A technician can use crucible tongs to add metal, glass, and other materials to a crucible for melting, and to reposition a crucible within a kiln. Once the melt is complete, the crucible tongs are available to carefully lift it out and transfer it to a shank for pouring. Shanks have a design that locks the crucible in place so it can be inverted, with one or two operators to control the speed and angle of the pour.
At a facility where metal, glass, and other hot materials are worked in crucibles and vials, there are usually several sets of tongs available. Operators can select the most appropriate size and shape for a given application, including two-person versions for very heavy crucibles that could be dangerous to lift alone. Like other tools, they need to be kept in a dry place when not in use, and should be regularly wiped down and oiled to remove dirt, rust, and other impurities that might compromise their performance.
It is possible to use other tools to handle a crucible, but caution is advised. These specialty tongs are built specifically for this application from materials thick and durable enough to handle the heat and weight. Other tongs may not be appropriate, as they could be too fragile to withstand regular use in the environment of an extremely hot kiln. The crucible tongs should bear a temperature rating along with usage recommendations.