Machining Stainless Steel
Machining and welding are a key part of the production of any steel structure. Steel comes in a variety of alloys, but none are more popular than carbon steel and stainless steel. Although both alloys share some characteristics that make them suitable for different applications, they also have differences.
Stainless steel consists mainly of chromium, nickel and molybdenum. It contains at least 10.5% chromium by weight or more. Carbon steel, on the other hand, is a composition of iron and carbon. The carbon content varies depending on the type of steel, starting from 0.05% for low or mild carbon steel and 3% for ultra-high carbon steel.
Stainless steel has a higher hardness and lower thermal conductivity, making it a challenging material to machine and requiring specialised machining tools and techniques.
Some practical tips for machining stainless steel:
- Select the Right Tools: Use cutting inserts specifically designed for stainless steel.
- Use the Right Cutting Geometry: Employ inserts or tool geometries designed for stainless steel machining. Positive rake angles and sharp cutting edges help in reducing cutting forces and improving chip evacuation.
- Optimise Cutting Speeds and Feeds: Stainless steel requires slower cutting speeds compared to other metals to avoid work hardening and excessive tool wear.
- Control Heat: Stainless steel has poor thermal conductivity, so heat buildup during machining can be a problem. Use a coolant or lubricant to reduce heat and prolong tool life. Coolants like water-soluble oils or synthetic coolants are commonly used.
- Avoid Carbon Steel Contamination: Avoid using tools or equipment made of carbon steel when working with stainless steel, as it can lead to contamination. If carbon steel tools must be used, ensure they are thoroughly cleaned and free from rust or other contaminants.
- Avoid Work Hardening: Stainless steel can work harden during machining, especially with improper techniques. Use sharp tools and avoid excessive pressure on the cutting edge to minimise work hardening
- Maintain Equipment: Regularly maintain and inspect machining equipment to ensure it’s in optimal condition. Dull or damaged tools can lead to poor surface finish and dimensional inaccuracies.
- Minimise Vibration: Vibrations can lead to poor surface finish and tool wear. Use proper tool holders, secure workpieces firmly, and maintain stable machining conditions to minimise vibrations.
- Experiment and Learn: Machining stainless steel may require some trial and error to find the best parameters for your specific application. Keep records of successful cutting parameters for future reference and continuously refine your machining processes.
WA-BM25S Stainless Steel Beveller
The WA-BM25S is an easy to use, portable, heavy-duty machine designed to machine stainless steel. The beveller is equipped with a powerful motor and fitted with a face milling bevelling head, allowing smooth operation and exceptional efficiency.
WA-BM25S allows milling of straight edges with a bevel width up to 25mm, and the variable spindle speed makes it easy to optimise cutting conditions. The machine features a continuously adjustable bevel angle between 0 and 90 degrees and milling depth for full control of the milling process. It is equipped with a roller guide, which make it easy and light to operate. All components of the guide are made of stainless steel to protect against contamination. The state of the art electronic motor overload module protects the operator, the machine and the tooling.