case carburising


In house capacity of 5 MT per day case carburizing heat treatment from DOWA Hi-Temp Japan, with 100% repeatability and accuracy of results charge wise, we control this furnace with SCADA with remote access and monitoring, records remain for 10 years. With a complete metallurgical laboratory working in background as a support system for the heat treatment. We offer more than 150 tons a month in production with heat treatment in Case Carburizing.


Carburizing is the process of adding additional carbon atoms to the surface and sub-surface of a steel, to increase surface hardness. This technique reinforces the metal part’s surface and improves its microstructure and mechanical properties by enabling carbon to diffuse into it. The depth at which carbon is able to diffuse depends on the type of material used, the level of carbon in the atmosphere, the temperature used, and the metal’s length of exposure to that temperature. The hardening happens only after the part is quenched (cooled), which locks the carbon into place.

In addition to improving surface hardness, carburizing enhances wear resistance and fatigue strength. It is best suited for low-carbon steels with carbon contents ranging from 0.05% to 0.3% and can be performed on parts of varying complexity. Carburizing is the treatment of choice for metals that require improved durability, wear resistance, and fatigue strength for their intended application.

After carburizing, the work is either slow cooled for later quench hardening, or quenched directly into oil. Quench selection is made to achieve the optimum properties with acceptable levels of dimensional change. Hot oil quenching may be used for minimal distortion, but may be limited in application by the strength requirements for the product. Alternatively, bearing races may be press quenched to maintain their dimensional tolerances, minimizing the need for excessive post heat treatment grinding. In some cases, product is tempered, then cryogenically processed to convert retained austenite to martensite, and then retempered.

The outcome of any heat treating method is essentially based on three variables: the temperature to which the metal is heated, the amount of time it is held at that temperature, and the method and rate of cooling. These variables are adjusted according to the type of material being treated and the desired effect of the treatment. Cooling can be achieved with gas, in salt, in air, or in oil.

Roll-fast is a metalworking company specializing in heat treating. We can achieve heating temperatures of up to 2400° F . The work we do supports various industries, from automobile, aerospace, Wind farms to computers and heavy equipment.

Carburizing Benefits

  • Hard and high wear resistance surface
  • Deep case depth potential
  • Improves durability
  • 55+ HRC

Typical Materials used for Carburizing

  • Low Carbon Alloy Steels (4120, 4820, 8620, 9310, etc)
  • Low Carbon Steels (1018, 1117, etc)

Components & parts we do case carburizing

Seat frames, seat belt buckles, hand tools, springs, axles, blades, nuts and bolts, Screws, Washer, nails, Gears, shafts etc.