JASCO employs a wide variety of heat treating processes which can alter the metallurgical properties of a part. Depending on the customer’s needs, the heat treatment can be used to soften, harden or strengthen the metal. It can also be used to temper or relieve stress without changing the part’s shape. Somewhat ironically, heat treating services can also employ extremely cold temperatures to achieve a desired effect. The primary heat treating services we utilize to fulfill our customers’ needs are listed below. Click on each to obtain further information.

case hardening

Case Hardening

Carburizing, Carbonitriding, Ferritic Nitrocarburizing, Nitriding, Gas Nitriding, Short Cycle Nitriding

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hardening tempering

Hardening & Tempering

Neutral Salt Bath, Induction Hardening, Vacuum Heat Treating, Age/Precipitation Hardening

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Bright, Full, Spheroidize, Normalize, Stress Relieving

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deep freeze

Deep Freeze

Cold Treatment (-120°F)

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Cryogenic Treatment (-320°F)

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steel shot

Special Processes

Steel Shot Blasting, Hardness Testing, Straightening

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Glossary of Useful Terms for
Understanding the Heat Treating Industry


An alloy is made of two or more elements, at least one of which must be a metal. The combined substance exhibits metallic properties.


This is a heat treating process used for ferrous metals. Its purpose is to increase hardness, impact resistance and fatigue strength. It also reduces part distortion. The process involves heating the part sufficiently to an austenitic phase where the microstructure is changed. It is then cooled rapidly to a point just above the martensitic start temperature, in order to avoid the pearlite phase. In steel, for example, the desired microstructure is bainite.


As its name implies, this heat process is used to remove gas from a metal.

Magnetic Annealing

This process is utilized on certain ferrous materials in order to achieve uniform magnetic properties. It requires particular attention to temperature control so that the magnetic properties are not lost.

Martempering / Marquenching

Martempering seeks to avoid the formation of bainite, pearlite and ferrite. Here the heat treatment transforms the metal from an austenitic phase to a martensitic phase, which is quickly followed by step quenching, usually in a salt bath. This step quenching reduces the thermal stresses usually associated with typical quenching processes, which will help to prevent cracking and minimize distortion.

Metal Oxide

This is a compound produced from the reaction of metal to oxygen. It allows a thin oxide coat to form which can protect the metal.

Nitriding Potential

During nitriding, nitrogen is diffused in a gas mixture into the surface of a metal. Its purpose is to increase surface strength. The nitriding potential is a calculation used to determine the probability of creating nitrogen layers of a determined structure. A higher potential generally results in richer nitrogen phases.


This involves aging the material at a higher temperature, for a longer time, or both. It results in loss of coherency, strength and hardness.

Partial Pressure

When a gas (or gases) is introduced into a heat treatment vacuum furnace, partial pressure refers to the force exerted by the gas which is constrained in the vacuum vessel. We introduce an inert gas at a controlled rate to set a partial pressure range which is then maintained during the heating cycle.

Solution Treating

We heat an alloy and then hold it at a suitable temperature until one, or more, of the constituent components enters a solid solution stage. At this point the solution is then cooled rapidly to hold the alloy in a condition which retains the solution’s properties.

Spring Temper

This is a steel temper process which is used to increase the upper limit of elasticity. It is obtained by hardening and tempering the steel and then reheating it until the steel turns blue.

Stopping Off

In order to prevent unwanted hardening in certain locations during the heating process, we apply a physical barrier to selected areas of the metal material before treatment. This barrier might consist of a specialized paint or copper plate.

Subcritical Annealing

This heat treatment process, typically in the range of 1300-1400° F, is used to produce a softened condition with less microstructural refinement than full annealing. It improves material ductility for subsequent cold-working or forming operations.

Vapor Pressure

The gas pressure which is exerted when a substance is in equilibrium with its own vapor. It is a function of both the substance itself and the temperature.