Why is Stainless Steel So Hard to Machine?

Stainless steel CNC manufacturing can experience challenges machining this alloy compared to softer metal alloys like aluminum and softer steels. CNC stainless steel service providers have much experience in processing this alloy but do consider its high strength, poor thermal conductivity and tendency to gummy up the Milling process. CNC technology does manufacture countless products out of a vast assortment of materials like copper, tungsten, titanium and aluminum in addition to stainless steel. A main reason stainless steel is widely used is that it is cost effective compared to some of the other alloys. To produce precision parts and components out of this popular metal series measures are taken from the knowledge of the how this material reacts when milled. CNC machining services professionals work through the following factors that can make machining stainless steel a challenge:

• High Strength and Work Hardening: Stainless steel has high tensile strength and gets stronger and more difficult to cut as the machining process goes forward. This requires more powerful machines and sharper cutting tools, increasing overall machining difficulty and time.
• Poor Thermal Conductivity: Unlike some other metals, stainless steel is a poor conductor of heat. This means during CNC stainless steel heat is generated during cutting and can concentrate in a localized areas around the cutting tool. This intensity of the heat can negatively affect the tool’s lifespan and the quality of the machined surface.
• Gummy Chips and Tool Welding: The high work hardening tendency and high cutting temperatures can lead to the formation of long, stringy chips. These can clog the cutting area and even weld themselves onto the cutting tool. This reduces efficiency and increases tool wear.
• High Cutting Forces: Due to the high strength of stainless steel, significant force is required to remove material during machining. This translates to increased wear and tear on the machine itself, requiring robust equipment and potentially slowing down the machining process.

Mitigation of the Challenges

Can stainless steel be machined? Of course, it can and is so in many ways for numerous industries and countless applications like aircraft engines, medical and surgical tools, shims, stages for optics and other precision machined components. To continue providing the high precision and quality produced by this technology, CNC machining mitigates the challenges of machining of stainless steel by several ways including:

• Use of Correct Cutting Tools: Specialized tools made from hard and wear-resistant materials like carbide or ceramic are used for stainless steel machining.
• Speeds and Feeds: This is a way to optimize the cutting parameters like the cutting speed, the feed rate and the type of coolant used to reduce heat during the process and extend tool life.
• Pre-machining Techniques: Techniques like annealing (heating and slow cooling) can be used to soften the stainless steel before machining, making it easier to cut.

With so many products and supporting parts and components made from stainless steel, these challenges don’t seem to be an issue for the industry. However, stainless steel CNC machining services do know each project has its own challenges in the design, the post finishing and other factors. For a material like stainless steel, products are supported through years of experience in precision manufacturing and all the little details involved. It’s incredible how these products are made with so many things that could go array, but they do make it and we are gifted with incredible products that enhance, transportation, medical care, food production, communication and our overall health and wellbeing. If you’re considering using stainless steel CNC Milling for your next project, you can be assured that a high precision component will be manufactured.