Heat treatment improves the properties of the material.
We utilize a variety of equipment to handle a wide range of heat treatments.

Heat treatment is a processing technology that applies heating or cooling to metal to improve its properties without changing its shape. Processing conditions can be determined in consideration of product performance requirements, and properties such as hardness, viscosity, impact resistance, wear resistance, corrosion resistance, machinability, and cold workability can be changed.
DPI has equipment such as vacuum furnaces, electric furnaces, and continuous furnaces. We then perform appropriate heat treatment to match the hardness and strength required for the product.


This is a process in which steel is hardened by maintaining it at a temperature above its transformation point and then rapidly cooling it.


When steel is quenched and hardened, it becomes brittle. Therefore, it is heated again (tempered) to increase its toughness.


When external force is applied during cutting or press processing, a repulsive force may remain inside the metal, which may lead to premature failure of the metal. Annealing removes these residual stresses and processing-induced hardening. is also used to soften materials and make them easier to process before machining.


When steel materials are made by forging, casting, or rolling, the process causes distortion, making the structure of the steel uneven. Therefore, normalizing is performed to make the structure uniform and finer, thereby improving machinability. Normalizing increases strength and ductility and removes residual stress, so it is also used as a pre-quenching treatment.

Solution treatment

This is a treatment mainly used for stainless steel. Solution treatment before processing removes precipitates that degrade corrosion resistance and improves the steel structure.

Aging treatment (precipitation hardening treatment)

Aging refers to changes in properties such as hardness and corrosion resistance over time. Aging treatment is a process in which temperature is further applied to accelerate time transformation. Precipitation hardened materials are soft to make them easier to process, so after processing they are aged at a certain temperature to achieve the desired hardness.


From design to manufacturing and quality control,
DPI will use its unique know-how
to meet your requests.

Inquiries TEL
03-5956-9175 (Parts business)/03-5956-9176 (Coupling business)
Business hours: 9:00 a.m. - 5:00 p.m.
(Excluding Saturdays, Sundays, holidays, and our company's holidays)

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