Improved Machinability Offered By New Project 7000® Stainless Type 203

August, 1996 - Superior machinability is offered by a new stainless steel from Carpenter Technology Corp., Reading, PA, known as Project 7000® stainless Type 203.

The new alloy is expected to provide productivity gains of 30% to 50% over generic stainless Type 203, and substantially better machinability than that possible with Project 70® stainless Type 203, which has been well known for its free-machining characteristics.

Carpenter notes that the new stainless, which has physical and mechanical properties similar to Type 303 stainless, represents the latest addition to the company's recently introduced Project 7000 series of stainless steels.

A bundle of Carpenter Technology's new Project 7000® stainless Type 203 available in 1/4" to 3/4" dia. bar sizes.

Project 7000 stainless Type 203 can be considered as an alternative to the conventional resulfurized austenitic stainless steel known as Type 303. Some machinists prefer Type 203 stainless for its drilling characteristics, while others prefer it for jobs that permit the use of maximum form turning speeds. In other cases, the alloy's effect on tool life, or its machined surface capabilities may be determining factors in its selection.

Machinability can be evaluated in several ways, including machining speeds, surface finish and tool life. The user's measure of good machinability may depend on the combination of machining operations involved, along with factors such as part geometry, print tolerance and surface finish requirements.

As with all grades in the Project 7000 stainless series, the new Project 7000 stainless Type 203 will offer greatest advantage in operations using large volumes of small diameter bar stock on long production runs of complex parts, particularly in high technology plants that routinely track costs and have machines capable of running at higher speeds.

Nominal analysis of the new stainless is: carbon 0.08% max., manganese 5.00/6.50%, phosphorous 0.040% max., sulfur 0.18/0.35%, silicon 1.00% max., chromium - 16.00/18.00, nickel 5.00/6.50%, copper 1.75/2.25, molybdenum 0.50% max.

As noted in the composition, high manganese and copper have been substituted for some of the nickel, resulting in a stable austenitic structure with low magnetic permeability.

This stainless steel can be considered for applications such as fittings, valve bodies and shafts, automotive hardware, electronics fasteners and ordnance components.

Project 7000 stainless Type 203 is a premium alloy available in minimum mill quantities in bar sizes ranging from 1/4" to 3/4" diameter.