Stainless steel is one of the most sought after materials for both customers and manufacturers to utilize in their everyday operations. Machining stainless steel is popular as steel comes in multiple grades and provides a number of benefits and features, making it suitable for various applications. To be classified as stainless steel, it must contain a minimum of 10% chromium, an element that grants stainless steel with its many unique properties such as resistance to corrosion and the ability to heal itself in the presence of oxygen.
Stainless Steel Benefits
Stainless steel offers numerous advantages for use in industrial machining applications, including:
- Strength. Stainless steel machining is popular due to its superior strength-to-weight ratio, which allows parts to be machined from thinner materials. Since stainless steel can withstand extreme temperatures, its strength can be further improved by cold hardening and heat curing processes to suit the intended application. Among the different metallurgical structures of stainless steel, martensitic stainless steels are capable of the highest strengths.
- Highly Versatile and Flexible. The flexibility of stainless steel allows it to be formed, welded, cut, and machined as easily as traditional steels. Sulfur can be added to further increase its formability, however, austenitic stainless steel is generally considered the most formable and versatile variation while other metallurgical structures tend to be brittle. The combination of stainless steel's formability and today's innovative manufacturing techniques allow it to be used across a variety of applications.
- Corrosion Resistance. Stainless steel has high corrosion resistance, allowing it to be used in multiple environments. Low alloyed grades of steel are capable of resisting atmospheric conditions while high alloyed grades can withstand exposure to acids, chloride, and alkaline solutions. Grades of austenitic stainless steel that contain higher amounts of chromium boast a higher resistance to corrosive environments.
- Low Maintenance and Durable. Stainless steel is preferred for industrial machining applications as it requires a low level of maintenance. Steel can also withstand harsh environments and a wide range in temperature. These combined properties result in a longer life cycle at a cost-efficient price when measured against other metals.
- Aesthetic Appeal. Stainless steel is available in many surface finishes, creating an attractive and modern appearance to complement any kitchen, home design, and theme.
In comparison to metals such as Inconel, brass, nickel, and titanium, stainless steel offers stronger resistances and longer life cycles at a better cost. Non-metallic materials like plastic, glass, and ceramics are weaker, less durable, and cannot withstand the extreme temperatures and corrosive elements that stainless steel can, making them less attractive for machining purposes.
Stainless Steel Grades & Uses
There are a variety of stainless steel grades that are used across different applications, including:
- Austenitic Stainless Steels. Ardel Engineering offers a variety of austenitic stainless steels, including Grades 304, 304L, 316, and 316L. Grades 304 and 304L are considered general use alloys of stainless steel ideal for components that require extensive forming or welding. Grade 316 is popular in scientific applications such as those found in laboratories, hospitals, and marine environments as it is highly resistant to heat and corrosion. Grade 316L has an extra low carbon analysis, which prevents harmful precipitation during welding applications. The primary difference between Grades 304 and 316 is the presence of molybdenum in Grade 316 that allows for superior resistance to chlorides.
- Ferritic Stainless Steels. Ferritic stainless steels offer great formability and are commonly used in appliances, axles, shafts, and fasteners.
- Martensitic Stainless Steels. Martensitic stainless steels tend to be more brittle but offer high strengths, making them suitable for general purposes, knives, bearings, and other wear resistant applications.
- Precipitation Hardened Stainless Steels. Precipitation hardened stainless steels are high strength steels typically used in aerospace valves, fittings, and fasteners.
- Duplex Stainless Steels. Duplex stainless steels are used to avoid stress corrosion in applications such as heat exchangers and pressure vessels.
Machining Stainless Steels
Different metal forming techniques and equipment can be utilized depending on the grade of stainless steel and its intended application.
- CNC machining is used to precisely craft components with high repeatability and small tolerances.
- Swiss screw machining provides a cost-effective option for both short and long runs.
- Other techniques such as EDM and Vertical & Horizontal milling are also commonly used to machine and form stainless steel.