Relative Cost Data For Common Stainless Steels
The following guidelines will assist you in choosing the most economical grade of stainless steel for a particular application. The listing that follows ranks some of the stainless steels by decreasing cost, (Type 330 the most expensive) and by decreasing corrosion resistance (Type 409 being the least corrosion resistant). Cost relationship may vary by product form.
It is important to take into account the overall, or end use, cost for a product or application when considering the use of a stainless steel alloy instead of carbon steel. When total service life is considered the use of a stainless steel often is not as expensive as would be thought from just comparing material cost alone. Long life free from, or with minimal, maintenance (cleaning, painting, repair or replacement) may enable stainless steels to provide an attractive economic picture for many applications. The engineer's objective is to select and use the least expensive material which will meet the requirements of the service conditions, and perform in a safe and reliable manner over the desired service life of the equipment. When fabrication, installation, and maintenance costs are factored into the overall picture, in addition to the cost of the raw materials, it is often found that the most durable material is only slightly more expensive than the least durable. In comparing costs, it is desirable to consider costs under the following general headings.
1. Cost of raw materials
2. Manufactured cost - Materials plus labor to manufacture. Includes items such as pumps, valves, filters, pipe, fittings, pressure vessels, heat exchangers, etc.
3. Installed cost - Manufactured cost plus labor to install. The cost of installing piping greatly alters the comparative costs of the pipe and fittings.
4. Life cycle, or maintenance and repair costs - The costs of periodic maintenance and renewal can make the lower cost material the most expensive to use in the long run.