Carburizing is a case-hardening treatment where a part is exposed to carburizing atmosphere at a high temperature. This treatment creates a surface (case) with an elevated carbon content. The carburized part can be said to compromise a kind of composite material, where the carburized surface is hard but the unaffected core is tough. This gives the part a very fine combination of properties with high strength, wear resistance and toughness.


Carbonitriding is often applied for steels that have a lower alloying content than the carburizing steels. In the carbonitriding process, carbon is added to the surface in the same manner as in case hardening, but in addition nitrogen is supplied by the addition of ammonia to the atmosphere. The nitrogen increases hardenability and compensates for the lower alloying content of the steel. It is therefore possible to surface-harden low-alloy and carbon steels by means of carbonitriding.


Normalizing (atmosphere and non-atmosphere) is heating a ferrous alloy to a suitable temperature above the transformation range and then cooling in air to a temperature substantially below the transformation range.

Annealing/Atmosphere Annealing

Annealing is a generic term denoting a treatment consisting of heating to and holding at a suitable temperature followed by cooling at a suitable rate, used primarily to soften metallic materials, but also to simultaneously produce desired changes in other properties or in microstructure. The purpose is, but not restricted to, improvement of machinability, facilitation of cold work, improvement of mechanical or electrical properties, and/or increase in stability of dimensions.

Stress Relieving

Stress relieving is heating to a suitable temperature, holding long enough to reduce residual stresses, and then cooling slowly enough to minimize the development of new residual stresses.

Shot Blasting

Shot Blasting is the process of removing scale, rust, oil, dirt and grimes from your parts. GFI is rated to handle over 20,000 lbs per hour. We use a metal shot and a glass bead in various machines to obtain the customers desired finish. Our machines are rated to handle the toughest Almen specs, and we can provide our customers with Almen strip Certifications on request.

Neutral Harderning Quench and Temper

Hardening and tempering produces adequate strength and toughness on parts which will be highly stressed. The strength and toughness are adjusted to different levels by choosing different tempering temperatures.

Problem Solving

Is your heat treat supplier or your heat treat operation not performing consistently by not giving you the quality or dimensional stability you expect? We can help. We have solved many problems related to: