Benchtop Draw Furnaces / Tempering Furnaces
Draw furnaces (also known as tempering furnaces) are used for tempering and other low temperature processes. They normally operate at temperatures below red heat range where heat transfer to the tool steel is accomplished by the process of convection heat transfer. Our Cress benchtop draw furnaces / tempering furnaces are easy to operate, have long-lasting durability, and efficiently improve your workflow. All Cress heat treatment furnace cases are constructed of heavy gauge sheet steel and finished in gray hammertone, and the walls and doors are constructed of the finest quality insulating fire brick backed up by 1800°F block insulation.
How Draw Furnaces / Tempering Furnaces Work:
Cress Draw Furnaces, also referred to as Tempering Furnaces, are generally rated for temperatures up to 1250°F, and are used to relax the stresses introduced by quenching a metal part after high temperature heat treating.
Metal parts that are forged and then machined have internal grain structures that are not uniform. Under consistent use, the metal part can fail due to varying resistance in the part to bending, or other forms of wear. High temperature heat treating in a draw furnace (tempering furnace) is used to allow the internal grain structure to become uniform. Once that is accomplished, if the part is allowed to then cool slowly, the grain structure can return to its original state. This defeats the purpose of high temperature heat treating. For that reason the part is taken out of the draw furnace at the high temperatures, and immediately lowered into a quench tank, freezing the grain structure. The quench, however, causes stresses in the part due to the outside being subjected to cold temperatures before the interior. To relieve this stress the part is placed in a draw furnace (tempering furnace), which is then taken to lower temperatures that are sufficient to relax the stress, and allow the part to have an extended usable life without failure due to internal stresses or non-uniform grain structure.
Cress Draw Furnaces / Tempering Furnaces are supplied either as single chamber furnace units, or as the lower chamber of a dual-chamber furnace unit.
Our Benchtop Draw Furnace / Tempering Furnace Options Include:
Stands and quench tanks
Audible process alarms
High limit safety thermostats