304 Stainless Steel vs 316 Stainless Steel

Stainless steel is a widely used material in medical applications due to its versatility, corrosion resistance, and cost-effectiveness. At Component Supply, our 304 and 316 stainless steel mandrel wire stock is spring tempered, drawn, and straightened with a bright finish. When viewing the two stainless steel wires, you may not see an apparent difference in appearance. However, the two differ in chemical composition and application uses.

304 stainless steel contains 18% chromium and 8% nickel. 316 stainless steel contains 16% chromium, 10% nickel, and 2% molybdenum. The distinguishable difference between 316 from 304 is that 316 contains molybdenum, which aids in corrosion resistance to chlorides. Due to its higher corrosion resistance, 316’s lifespan will be longer than 304’s, specifically when used in highly acidic conditions. 316 contains less chromium than 304, reducing the hardness and decreasing the tensile strength. Therefore, the uses for 316 will slightly differ from 304’s. Many researchers are quick to remember only the positive attributes of 316 compared to 304 without fully considering the adverse effects in chromium may cause.

Generally, 304 Stainless Steel is the most popular choice in wire because it is less expensive and has a high tensile strength. In other cases, 316 might be preferred over 304 if your application occurs in a highly acidic atmosphere, and slightly lower tensile strength is sufficient. When it comes to application, you must weigh the longevity versus the strength of the stainless steels. 

In the medical industry, 304 and 316 are both commonly used. Medical devices utilizing 316 stainless steel have more reusable life than 304. Because of their higher rust resistance, they can undergo continuous sterilization for extended periods. For example, it is common to use 316 ss as temporary rods and pins in a medical procedure. Still, if the rods and pins are permanent, a more durable metal would need to be used, such as nitinol or titanium. Medical devices containing 304 are standard tools that are less expensive and are discarded after use, such as a scalpel. 304 is acceptable in most scope procedures or outpatient surgeries such as dentistry, vascular therapy, orthodontics, and endoscopy. Other demands include Aerospace (high-performance wire and cable, fasteners, springs), Industrial: springs, resistors, jewelry. 316 is more commonly used in marine applications where it is exposed to harsh acidic conditions. More potential end-uses of 304 and 316 include catheters, mandrels, stylets, introducers, push-pull rods, guidewire assembly. However, while 304 and 316 are high-quality metals that will have longevity, over time, rust will begin to form when exposed to oxides, an inevitability with any ferrous metal.

Component Supply is not always aware of the end-uses of our researchers’ applications. Suppose you’re still unsure which material is the most suitable for your application. In that case, we advise purchasing a small quantity of either material to test with before committing to a larger quantity.