In any custom sheet metal basket application, the material that your basket is made of can be just as important as the design of the basket itself. With the right material, your basket will be able to withstand the stresses of your process for years or decades of use. With the wrong material, a basket will fail early, exposing your workers to potential harm, and your parts/machinery to damage.
One of the most popular materials for sheet metal baskets is stainless steel, as this material possesses a high resistance to corrosion, scaling, and extreme temperatures as well as having high tensile strength. While stainless steel is a household name, what many people do not realize is just how many different stainless steel alloys are available on the market today. All told, there are well over 300 different varieties of stainless steel available on the market.
So, which grade of stainless steel is right for your sheet metal basket application? The answer to this question depends on a lot of factors, such as what your basket application is, what chemicals, temperatures, and environments the basket will be exposed to as well as your budget for the baskets and how many you’ll need.
To help you find the right type of stainless steel for your basket, here are a few common factors that influence material choice and which materials might be best for such applications:
Highly Corrosive Chemicals
Many sheet metal basket applications involve the use of caustic materials to clean parts or expunge contaminants. When exposed to heavy corrosives, plain steel tends to corrode very quickly. Different grades of stainless steel, on the other hand, tend to have varying levels of resistance to corrosive chemicals.
The most commonly used grades of stainless steel for applications involving corrosive materials include grade 304 stainless steel and grade 316 stainless steel. Grades 304 and 316 are both austenitic stainless steels, which are among the most common stainless steel alloys on the market.
Grade 304 stainless is a general purpose alloy that is useful for a variety of tasks because of its balance of corrosion resistance, tensile strength, and temperature tolerance. This material is commonly used in immersive wash processes where the basket may be submerged for prolonged periods of time.
For especially caustic applications, such as ones involving food, biomedical, and marine applications, grade 316 stainless steel is even better than grade 304 stainless steel for resisting pitting and corrosion, and has an even higher tensile strength. This steel alloy features more nickel and molybdenum content than grade 304 does, which tends to make grade 316 steel more expensive than grade 304.
Many processes, such as parts sterilization or heat treating, tend to employ extreme temperatures to get parts finished. While effective for eliminating biological contaminants and the like, high temperature processes do tend to put a lot of stress on a basket.
Many different types of stainless steel tend to have a very high temperature tolerance, which is what makes them superior to plastic baskets for high temperature applications (steel alloys can take up to 1600° F, plastics can typically only survive exposure to temperatures in the 200-300° F range).
An example of a stainless steel alloy that would be ideal for extreme-temperature applications would be grade 330SS. This material is able to withstand temperatures up to 1900° F (940° C) while retaining its tensile strength. This prevents the basket from becoming deformed by heat stress and the weight of held parts even as your finishing process reaches peak temperature.
Grade 330 stainless steel is typically more cost-effective than Inconel for high-temperature applications, but is more expensive than grade 316SS.
When you’re making a basket order, chances are that you have a use for that basket either now or in the immediate future. So, you naturally want your basket order to be filled ASAP.
How does your choice of basket material affect your delivery time?
To put it simply, most manufacturers typically stock only the most commonly-ordered materials, such as grade 304 and 316 stainless steel. Other, more uncommon grades of stainless steel have to be specially-ordered by the manufacturer, who then has to wait on shipping of the raw material to begin work on your order.
The amount of delay caused by ordering a rarer material is a bit random, as it depends on the manufacturer’s supplier and how quickly and reliably they can ship material.
Cost of the Material
While using the right stainless steel alloy for the job does maximize the useful life of your baskets so that you don’t have to keep reordering the same basket again and again, sometimes there isn’t enough room in the budget to order the number of baskets you need using the best material for the job. This is where cost considerations come into play for your basket material choice.
When designing a custom basket for your application, a design engineer can make a list of materials that are desirable and ones that are acceptable for the application based on the process the basket will be exposed to.
Marlin Steel’s engineers, for example, use Autodesk software to test basket designs to see if the material of the basket will stand up to a given process over the course of thousands of uses. This way, it is possible to determine if a given material will be enough to meet your needs without having to go to the time-consuming expense of making dozens of prototype baskets and testing them on-site. The benefit of doing this is that it allows you to reliably find the most cost-effective material for your application to fit your budget.
However, there are many instances where a material that costs a little bit more will last twice as long, actually reducing your long-term costs for your baskets.
So, which grade of stainless steel is right for your basket application? Contact Marlin Steel’s experienced, degreed mechanical engineers to find out!